LOL we know the publicized sucker price for a TSMC 5nm wafer (which Nvidia pays less than being a top customer) and the size of the 5080 die. The chip itself costs somewhere between $100 - $150 depending on yields and Nvidia's unknown wafer discount rate. GDDR6 was $2 - $3 per GB, GDDR7 is probably a little more, but not substantially so. The complete 5080 board costs like $200 at worst, maybe $250 if you really want to be safe and wildly overestimate every component and step
I would absolutely believe that Nvidia sells this $200 board to the AIBs for $800 though.