To be honest , i took as granted that almost all of us , have atleast one of each NV core.
But still , cant be that expensive ... (i see most price range is from 15 to 70 euro and the geforce256 is the most expensive at 90++)
https://www.ebay.at/sch/i.html?item=395320642025&rt=nc&_ssn=henengelber0&_pgn=1
https://www.ebay.at/sch/i.html?_nkw=geforce+4+ti&_sop=2