I would look on Bricklink first for a general idea of what individual pieces are going for. Bricklink has a good deal of price information. Normally, I would expect Ebay prices to be more, but you may get lucky. Personally, I would not buy on Ebay. The quality from Bricklink sellers has for the most part been better. Of course, there are those here that buy and sell a lot on Ebay and like it.
Power corrupts, and absolute power corrupts absolutely!
Despise learning and make everyone pay for your ignorance.
The water that floats a ship is the same that sinks it.
My LEGO figures keep me from being evil, drat!!