You can get anythign you want on ACRIS, the Governmentt database...they began including Coop slaes a few years ago.
Or your agent ought to be able to get them for you.

Hi Paul-

Streeteasy.com will have a search box where you could type the address and see if any past sales appear.

Typically co-op sales are harder to find than condos. If you are looking to make an offer on a property or are trying to find out what your apartment is worth, the most worthwhile comps will be those apartments that are currently in-contract. That will give you the best idea of value, because comps of 6 months or even 4 months ago will not be indicitive of today's market.

I can run a search for these in-contract sales for you, just email me the address of the building and the type of unit and line you are looking for.

Best of luck.

Morgan Evans
Prudential Douglas Elliman
morgan.evans@elliman.com