Well, as someone who has sold a bit of MTG cards on Ebay, I have to say that you can't expect to get what they are actually worth. Some cards are worth a lot, but some aren't really worth anything.
If you just want to get it over and done with, put all your cards on as a lot. My personal recommendation though, is to use Ebay, Scrye Magazine, etc... to price the more expensive cards. List those as your major auctions, then just stick the rest in serveral lots. Hope this helped!