Last time I ran out of tooling leather for sheaths I ordered a 9-10oz double shoulder. What was shipped was the largest double shoulder I've ever seen at ~24 sq ft!! Even if they had shipped what I was expecting (10sq ft) that's still more leather than I'll go through in a few years at the rate I'm going. So...
$9.00 per sq ft gets it to your door. That's less than what the knife supply places charge you (w/o shipping even) and about what you'd pay at Tandy, without having to buy the whole thing.
First come, first served until it gets down to the amount I think I'd like to keep on hand.