I need Polaroid film! ?

I have searched high and low for Polaroid film at a price that won't drain me completely... If the impossible project had any 600 film in stock I would buy it. My camera is a 660 sun. I bought a pack of film with it but it expired in '93 and I would prefer to keep it in the mint condition it is in. I managed to get the camera and the film for only $17. So please, if you have any ideas on where I can find 600 film for a price below $50 please let me know! Also I have looked on craigalist and eBay and lomography.