You're looking for one of the hottest products on the market at the moment. I'm actually surprised that we are not seeing more people here chasing this gear, but trust me, you are going to need a lot of luck finding any source with any margin at the moment.
You're best bet is yard sales I reckon, see if you can dig up some old albums that some idiot is tossing. I've picked up a great collection of vinyl over the years, figure they have to die sooner or later, and if I can out last them I'll have a chance to benefit LOL