You have a couple of options.
1) Not sure how close to Buffalo you are, and how bad you want to purchase a lower face to face but you could try Buffalo Gun Center on Harlem Road. They have alot of good stuff there but it is way overpriced. These guys wrote the book on price-gouging.
2) Use the FFL search on Gunbroker.com and get yourself hooked up with a dealer that you can trust. You can then purchase a lower from the for sale forums here and at other sites, but obviously this would be the most cogent choice as this is the pre-eminent home of the ar-15 on the web. The dealer can fax, send or email his FFL license number to the seller and have a lower sent to him where you would go and do the ATF papperwork. I did several transfers with a dealer out of NorthTonowanda and would highly suggest him if you are in that area. I can give you details via PM or Email
The going rate for FFL's is about $20-$30. I would look into "Mega Lowers" in the for sale forum from seller "Iblis". $89 for a stripped lower and $149 with a LPK installed.When i first got into the ar15 game, i bought 2 from him and the lowers as well as customer service were both top notch. You wont be dissapointed.
Good luck