Firstly, welcome to the forums. Secondly, we don't allow selling of any items on the forums. However, I can offer some advice on your question. The price you choose to sell them at should be what you feel best. This means if some are too high and some too low, find a middle ground. The best way I'd suggest is by using BrickLink and looking at the figures or pieces and then do a search on their pricing. To narrow it down, you can search by your own country and then look at the price range and choose somewhere in there that you are comfortable with. I plan to open a BL store hopefully this summer and the method I'll be choosing is to search item, minifig, or set and then look at that based on my country (the US). This is a good starting point, but ultimately, you should pick whatever makes you feel you will be happy with in return.
"I might be a few bricks short of a wall, but they are Lego bricks. Watch where you step, because they hurt like a #*%$#"