My guess is that much like the way it is with other forms of media, people might often believe that physical stuff over digital stuff automatically brings it at a higher value. For example a paperback book almost always costs more than a digital form of the same book, and the same with movies, and lots of other things.

(Está bien si escribo en español?)

Pienso que les da igual el tiempo y esfuerzo que inviertas en el dibujo, ellos cuentan con lo que gastes materialmente, y como en un dibujo digital no estás usando papel, lápiz, rotuladores, acuarelas o lo que se venga usando, pues debería costarles menos.

Y esa es la mentalidad que rige el mundo.

i agree, its like how people think my tattoos shouldnt cost so much.....yet they forget its on them they're whole life

It has already been stated here, but if one assumes the price for the artist's time and effort is the same regardless of medium, then logically there will be a difference in price based on materials.
In digital art we have to buy pretty expensive single pieces of equipment. A computer, tablet, monitor, mouse, keyboard, scanner, printer, paper and ink cartridges, and the ever changing software that is available to us at the time. For a lot of us this comes down to a heafty start up cost and a not so small replacement/upgrade cost in the hundreds if not thousands of dollars.
One could argue that the workspace of a desk and chair, while different, is about comparable in price, regardless of the mediums they are designed to support. And we should not go into the difference in electricity consumption or space consumption as that is not pertinent to this particular topic.
Traditional art materials will cost much much less per item but they are consumable and some have shelf lives. Pencils, graphite, pens, ink, paint, brushes, erasers, chemicals, blades, etc. the list is much larger. One might argue, depending on their medium, that storage and consumption of traditional materials in the long term can far outweigh that of digital media in exchange for the physicality and permanence of "real" media as opposed to the relative insecurity of digital data storage.

Now, there is no argument that digital production is much more forgiving. But as to how fast it is depends on the artist and the project. So if one assumes that an artist charges the same for their time and effort regardless of media, and that in say 1 years time they will be charging to recoup their costs of materials, then it becomes a question of how much and how fast they can produce. If an artist is paying off a new computer it's going to take longer than paying off a set of paints.

Then there's the cost of storage space. In digital this usually comes as an external memory device whereas in traditional you'll have some corner, a portfolio, a flat drawer, or maybe even a safe.

We are in the digital age and at the height of consumer technology. This means that you can find a digital or traditional image online somewhere if you look in the right place. And that can be found and kept digitally for free. For the sake of this we will assume that is a universal base line.
After that the cost of printing also becomes universal depending on the printers desired results. Cost of selling prints comes down to the seller, the cost to make their prints and how many prints they've made compared to the expectation of time it will take to move all those prints.
If we assume this, what it actually translates to is that a traditional artist has the option of selling the original for a much greater price than a print or the cost of time and production or even material recoup. The digital artist does not have this option.

Now one might try to argue that this gives the traditional artist an advantage in making money by having more options for physical sale. BUT as we all know that depends on the artist, the piece, the fandom, and who is willing to blow several hundred dollars on a painting, transport it, then store or display it. And we should all know by now that there is always somebody who will buy it if given the opportunity regardless of price, but they may not ever get their opportunity. A high sale value item that does not sell might as well not exist, in business terms.

Then there's also the argument of the value between custom made work vs mass production work. One can argue that the only real difference between the two is the intention for the commission. A personal commission, like the ones we produce in places like DA, is produced by an individual or small group for private use or small scale public display with limited printing and sale potential and value. A mass production piece tends to be purchased by a large group or company with the intention of mass printing and high sale potential, which gives the artist a chance at a higher pay check.

So to sum up, in a generalization, for one to assume that cost of paints and materials is all that it takes to determine digital work should cost not only less but a LOT less is naive. I would make the argument that digital sketching is faster and more forgiving, but I can ONLY say that NOW after having had years of practice with both mediums. In reality, it is a question of the particular artist.
So digital does NOT equal CHEAP, it's just different.
I think people should spend more time deciding for themselves wether or not A) they are willing to pay what a particular artist is asking B) the artist is even worth what they are asking. After that it doesn't really matter what they're charging.

I'd sum it up in one word. Reproductions. I've had commissioners basically bring up the fact that they want to be the only one to have a copy. Otherwise I can sell prints. I did some digital prints double sided on acrylic sheets and they ended up being hard to produce and so limited that I ended up getting much more for each one. Just make it special and you'll get that premium price.

Assuming that the artist deems the value of the time and work put into both pieces, the same; then I would expect the price for a copy to be the same. But I would also expect the original of the traditional piece to cost more. A copy is a copy, and every copy will look the same but there is both sentimental value and sheer marketing value in the original of a traditional piece which needs to be added to the price.

I think traditional or digital have their own challenges. To say one is 'easier' than the other is just silly. I think the only real argument for digital art being cheaper is that there's no physical copy to hold in your hand.

I think traditional should cost more. Not because of the time and effort (which can be the same amount of time if you have to retry a piece several times over) but because of the cost of supplies.
Once you buy a computer and you pay for photoshop or a similiar program (which yes is more expensive especially if you keep updating it) but it's a one time buy, whereas in traditional art you spend more money on pencils, paper, paints, brushes, canvas, etc. Then if you don't have the skill to accomplish a piece on the first try, you have to try again, costing more paper, pencil, etc.

That's probably the only reason why most people want digital art to be cheap, because of the cost of your art supplies. I don't think they either realize how hard and time consuming digital is or not, they just assume it's easier because you see it more often. So when you see it more often it must be easier and therefore cheaper.

I've tried digital art, and I personally think it's way harder than traditional.
With digital, I don't have the cintiq type tablet where you can draw directly on the screen- I have the bamboo. So it's weird not putting your pen right where you want to draw/paint. I'm so bad at it for this reason (and lack of practice of course)
I'm decent at traditional painting, and I find it easier because you can tilt the paper and let it flow (like watercolor) while you can't do that digitally.
I have a ton of respect for digital artists for this reason.

The price should be based on how much time and effort it took for the artist to make it.