What is with the sudden demand and price jump for these new diecast prototypes, especially from Jeff Gordon's and Dale Jr.'s charity sites on Ebay? The last one I bought was for around $300, (It was the Dale Jr. National Guard Pink CC Auto'd and it was prior to that car's actual release) and now it seems you can't touch one for less than $700-$800. I understand most of these are auto'd and pre-release cars, but buyers are putting out a lot more money for these cars in the last year or so. On the other side of that, older prototypes (even hard to find ones), seem to just sit there with minimal or no offers or sell for next to nothing. Is that because the production car is already released?