Well so far I havn't paid a penny for the game, and I'm level 21, with Rammus, Tryndamere and xin unlocked, no skins, and 350 RP (free as compensation for that weak of instability a while back). I would pay money if I thought there was something realy worthwhile but to be honest there isn't, and I think the better looking skins are too expensive. If I do want a great skin I'll just download it and use it myself client side for free, doesn't change anything if others can't see it.
As for the game initialy costing money before it became free, I think that is nothing compared to how much money they make now that the game has grown in insane rates after becoming free and gaining in popularity.
Regardless of how much money they make I think it's just a case of the game is growing many times faster than the devs expected and they can't keep up with the growing need for extra capacity, in a month or two I would expect it to be much better and hopefully reduced/no queues.