Wow, talk about an advance pin student! You're beating me (it's taken me... 4 months to get to roughly 300 pins though... That's been pretty pricey >_<) by a long shot!
I have to say, when I was a total beginner, building my trading pin collection was the toughest! Getting pins? Just to trade them to get the pins that I wanted? But I want to keep all my pins! So I got started playing pin games. You "always win" (consolation prize) in these raffles! I know I sound like an ad, but seriously - lots of games have super LE prizes, some have ALL LE prizes, and LEs usually have a great level of trading power. So if you're interested in trading and don't have much to trade with, look into games - either you'll win "big" with something you wanted, or you'll win a great pin to trade with someone 🙂