Ok, between researching online and the cardbacks of the few I have, I think I have a better idea of what it would take to catch up. I don't necessarily care about all the variants, and am more interested in the basic characters for now.
I had picked up a He-Man way back when this line started, and didn't get around to getting the others at the time.in the past month I've gotten Skeletor, Teela, and Evil Lyn and I think I might be hooked. The problem is I don't know if I can bring myself to open them, kind of love the box art. It also logos like it may be pricier to pick up some of the other earlier ones I missed, so we will see. Thanks everyone for your help. Side note, also picked up a Marty McFly, and preordered the basketball Teen Wolf. I've been watching eBay for a Goonies Chunk to finish off that set too.