That's fine! I know folks who have done a lot with/through them so I'm comfortable, but that's a choice for me to make. Other people (like you) may not be, and that's fair. You get to decide what experiences are worth it for you, and what ones aren't.

A lot of contests do have price tags on them; the way I look at it is a paying-for-feedback thing, when I've done them. Some are more worth it than others. I know of very few contests that don't have a business on the side (Apex, Flame Tree, Baen) that are fee-less.