This is the tough part to keep in mind, and I think what Panther and I were talking about earlier.
It's REALLY easy to get caught up in the high spender mania with a game like this, and I think a combination of friend units and engaged boards like this or over at Reddit only make it worse. It's very, very hard not to compare and get jealous when you see the whales charging ahead into territory that is impossible to follow with mostly (or completely) F2P gaming.
But if you take a moment and step back, you can realize that the underlying game is still there, and there is a ton of fun in this game without getting into a unit frenzy or challenge frenzy. There will be trial and challenges you can't beat. That's okay. You don't have to beat them all. Move on, have some fun, and congratulate those that ARE able to beat them. Hopefully a few of them are on your friend list, which ipso facto means you win as well.
Plus, it really should be noted that there are quite a few members of this board that have absolutely monster teams that are F2P, or at the very least aren't "whales" by the usual definition. You never know when Lady Luck will roll your way, so just keep at it.
Of course, I say all of this today when I'm sitting pretty well with my team and no one has posted pics of their rainbow Gilgamesh pulls.....