Prints of this size sell for maybe $20 unless they were made by someone famous...
There's a -huge- difference between a mass produced $20 poster print by an unnamed, unknown photographer and a hand matted (and also matted, period) print sold directly by the artist. It's like the difference between going to wal-mart to buy a belt and buying a custom belt from a local leatherworking shop.
Think of it in different terms. The prints and the mats cost me $120 (a profit margin of $280 if I sold all the prints at $20) and that's not even factoring in the "labor" cost involved with the time spent taking/editing/printing/matting each photo. Even if I were to charge minimum wage for the total hours spent on each photo (even though it's very difficult to determine) I might say... 4 hours per photo (factor in the actual time spent taking the photo and however far I went out of my way), that's $35 with materials added in, $40 is the minimum I could charge to make a $5 profit on each print, and that's
minimum wage labor. The intrinsic nature of art is that it's a unique talent that can't be achieved by simply putting in enough hours.
Also it's worth noting that a print made by someone famous that isn't mass produced is going to sell for a
hell of a lot more than what I'm charging. Just because you think that's too much to pay for this doesn't mean it is.