retail and boxed are the same .
Go with the 3000+, as mentioned, the 10x multi is useless because the HTT on A64 boards clocks so high. Use the extra money to get something that WILL make a difference, such as a good video card (6800GT, etc.). In your other thread you mentioned getting value RAM which is an excellent choice. Use dividers and multipliers to get the performance that you want, and use the money you save to go up to the next platform of performance, like getting a good DFI mobo or a high end graphics card.