If you want a vintage gem...
Formerly in Old Town, the family-owned and operated Bizarre Bazaar is now next to IHOP on College Ave. They're pretty eclectic; mostly a used book store, but they have a pretty big selection of comics, movies and records.
I was under the impression they no longer carried new releases, but according to their Facebook page, they do have a bit of a selection of newer albums. However, if you want the records that come with pops, crackles and that certain musty smell, this is your place to set aside an afternoon and flip through crates of 'rare gems.'
I've walked out with Mamas and the Papas and Stevie Nicks albums ranging from $5-$20 before. Bizarre Bazaar does buy used vinyl, though sometimes they are on a buying hold, so you may want to check before you head in.
Does: Carry used vinyl.
Does: Participate in Record Store Day.
Does: Buy used vinyl, and accepts donations.
Does: Sell and repair turntables.