Same here. I've sunk about $70 US on the game ($20 for the first champion pack, $30 for the second champion pack, $20 for the rune page bundle). I've mostly avoided buying skins and champions with RP.
I've got about 700 SR games, 300 bot games, 80+ Dominion games, so that's a huge chunk of time and it's been worth it.
P.S. Off-topic, but I think we're moving quickly into a marketplace where consumers will be directly paying artists for their work. We have to get used to supporting people whose work we value and enjoy.