It would depend on the leather. What kind, where in the side it comes from and so on.
I would say you could get good skirting, out of the very best area in a side for slightly less.
(about 11.00 a foot) If you went with number 2 grade you could drop anouther buck off that price. Number 2 grade will have slight blemishes that might not matter to your project and may be just as good in the long run.
Keep in mind that the best leather is close to the back bone, with the best of that in the butt. When you are buying by the side, all the leather below the break in the side is junk and can only be used as liner.( but you pay the tannery the same price as the stuff in the butt)
So most shops charge at a higher rate for the better leather to cover the cost of you leaving them with the junk. Or worse they will sell you the junk to cover the cost of buying the good stuff :(