The people who spend thousands on these things baffle me, but I'm cool with tossing them a few bucks if I played a lot of the game.
MWO: $60 founder, first F2P game I ever spent money on. Played it a lot until I got sick of PGI's incompetence, to this day barely used anything I got from being a founder.
Marvel Heroes: $20 at release, $70 recently (but I put about 350 more hours into the game). Looking back I regretted the $20 I spent, but now I wish I'd got the big expensive founder pack. Really impressed with what they did with the game.
Planetside 2: About $80 or so? Most of that was from a triple station cash sale and maintaining a subscription for a few months. Played it a LOT, never tracked how many hours but at least 250.
Warframe: $5, got a $20 pack 75% off on a steam sale. Honestly, paying money doesn't get you much in that game. Was waiting on a sale to buy some more shit but it never happened and I stopped playing.
Hawken: $10. Didn't play it much but I liked the concept. The playerbase was apparently too dumb to make objective-based gamemodes playable which was funny at first and then got annoying.
I have a friend who's never spent a dollar on an F2P game, and they're pretty much all he plays. He always did just fine in planetside and marvel heroes. He plays a lot of hearthstone too.