Nic, it's hard to give an opinion when we don't know what you have got. A bit of a general blurb about what sets you have and whether you have just base cards or base and inserts.
If you are unsure then do a search for Jeff Allenders House of Checklists, there is quite a comprehensive Marvel / DC section that lists all the sets that you probably have there.
Doing this allows non-sport collectors to give an opinion on what you have. Remember that it is only an opinion, you are best to look at what members here say and then do other research on eBay sold listings and other non-sport card forums or pages. For individual inserts have a look at COMC and that will give you an idea what inserts are going for as well.
Hope that was of some help.
Dave