Need affordable prime lens

Search locally for your lens. Something in the 24mm to 35mm would be good. I remember an old Tokina 28mm f/2.8 with fondness. If you search

http://forum.mflenses.com

you will find info on your possible purchases. Ask someone who has the Sony E mount NEX series camera what kind of adapters are available - presumably lots, because the mirrorless cameras are much less deep than the SLRs. Find your adapters on eBay or whatever the local equivalent is. These usually cost about US $6.00 (non-reporting) to US $10.00 (reporting). Ask a camera club member if they know someone who wants to sell an old manual focus lens. Consider old M42 mount and T mount lenses as well, adapters are easy to find.