I get my BLO at one of the big box stores, usually in the finishing/paint area.
I think walmart may have it as well.
As long as it is Boiled linseed oil.
(The straight linseed oil, which would probably be tougher to find, will take forever to dry).
Bill, I agree with John. The hardware & specialty stores are way too expensive. Oh yeah, they'll say there's is different, but it is the same thing. "Boiled" is the key word here.