I'm not sure... if you start counting since I got my first game with trophy support I'd say it took me around 9-10 months... if you start counting since I got my PS3 then it'd be around 1 year.
I think you need to get 6000 trophy points to get to Level 7.
Each retail game gives you 15 points for bronzes, 30 points for silvers, 90 points for golds and 180 points for the platinum, making a total of 1230 points (without counting DLC trophies...). The only exception to this (out of the games I played) is Final Fantasy XIII which only makes a total of 1215 points... it's as if it was missing a bronze... I don't know if other games do that.
That means the minimum ammount of games you need to get to level 7 is 5 (without DLC) because 1230 * 5 = 6150... but if you don't platinum all the games you get then you'll need more games to get to that level.
A banner stolen from some site xD
Release Final Fantasy Versus XIII nowwwwwwwwww!!! lol :P
