Been playing since mid-season 3 here. Owning every champion (will do soon anyway - been saving the purchase of the last 11 for Christmas), 20 filled runepages, owning every rune that I need (and some that I don't - bring it in, 3x Quint of Revival).
837942 IP earned total in 1306 days.
410400 IP spent on champions.
153799 IP spent on runes, including runepages.
38956 IP spent on icons.
210837 IP currently owned.
I know all this because I keep track of my every LoL purchase in an Excel document.
And despite all this, I do have a life. I think... Whatever a regular job is called these days. ^^
I'd used to stockpile 20k IP before purchasing anything, so I'd usually have around 40k or 50k IP when the sales began.
I used to do this too! :D
Started with 20k (any less, and you wouldn't really get anywhere), then 30k, then 50k, then 100k, then 150k...then I realized I had ran out of things to actually empty my IP wallet on.
I have 20 rune pages, all the runes I find useful and every champion unlocked.
So after all this, how much IP do you currently have? Sounds like 100k at least. :)
Btw, IP Chroma sale coming up. Should help get it going. ;)