Jive Time Records located on E Pine St in Capitol Hill specializes in Used rock LPs. This small store with two levels has some really great stuff. Used LPs are range from $4.99-$7.99. Upstairs are classical and a fairly large soundtrack section as well as sound effects records.
There are quite a few $0.99 cent bins outside the store as well as inside. I spent some time searching through them but most of it is bunk artists I have never heard of or Journey LPs.
Worth checking out though since a lot of records stores don't seem to have a decent selection of classic rock.