i really want to buy 
because i like Music based champions like sona, but i have a hard time getting IP, The sub-30 grinding is so hard it's impossible, i saved for 3 weeks to buy sona so i could get DJ Sona when it comes out.
any tips on how to get ip effeicently
buy ip boosts
otherwise play alot of games
play alot
alot
ALOT
of games
dont play custom games
if you are sub 30 play coop vs ai beginer or intermediate, do not play the intro ones as you will get less ip.
you can earn bonus ip for uop to 3 hours of playing bot games so roughly around 6-9 games a day playing bots and it should net you a nice little chunk within a few days. Play summoners rift and not twisted treeline as you are more likely to have a better game on the rift.
I generally do a bot game first thing to get my first win of the day and also help me warm up and practice new champs and i have played with diamond and plat level players all the way down to level 9 players it just varies day to day and time to time so you never know you could do an intermediate bot game with a bunch of high rankied players and it being a stomp in less than 20 or a bunch of low summoner levels and the game will be harder and may last 40-50 mins.
If you want to try pvp try playing aram they are generally shorter games and give a decent amount of ip for winning or loosing, the trouble though is trying to find a group of sub 30's playing aram.
ARAM, my friend You get more IP from a Loss on ARAM than from a win in Co-Op vs AI (allegedly) Also, games are usually shorter which means you can get more games in.
Forget about Coop vs Al. Play Aram and Normal mode. I farm 6300 IP in 8-10 days. I bought half of my champions with IP (Rek'Sai, LB, Ahri etc.)
you just play the game its not like your ip is going anywhere
For one thing, I try not to pay too close attention to the IP I get per game once I've set out to play for the day. Getting hooked on the numbers can be a bit of a downer. I also play with friends where I can, because even if I lose, I at least get to make memories with them along the way. I agree with some of the others that ARAM seems to be a good way to get IP and TT can be a bit too difficult. Definitely something to do more for a challenge, in my opinion.
Just play no rank PvP on Summoner's rift. And also I don't recommend Karthus if you don't like scary voices. Cause I feel like he stalks my soul.
