havent sony already done this with a SOCOM game on the PSP? where you buy it and it comes with a one-time use code to play online, then if you resell the 2nd hand buyer has to shell out again for another code to play online.
I think we live in a golden age of pricing, games appear on the Internet right away usually with at least £5 off the SRP, and if you wait a little the prices can fall quite quickly. generally i have been averaging £20 a game for a long while across all the formats that i own. I generally buy on the Internet from a popular etailer or in a shop if they happen to be doing a good deal on what i am after.... some great games can be had as bundle offers with other games too..