I'm 15 also and after buying a lot of lego, I think i'll take a brake till summer. Here is the list of stuff I brought in the past two months.
8 of the spring cleaning buckets (buy one get one free) each $8.50
11 4400 buckets each where 50% off at kroger for $7.50 (The total came up to 82.39)
I also bought 21 final dual II for $0.83 each
I bought one 7414 for $10.00
and one 7412 for $5.00
and a harry potter set for $15.00
The total comes to $162.45 so I saved myself $400 on lego.
From the buckets I added 109,000 to my collection
Hope this helps, and I suggest if you have akroger go check them out