Yes, same old crappy way of classifieds. I suggest using nasioc
Anyway, factor into your upgrade costs the fact that you need to buy a transmission for your WRX regardless. I mean, you can sell it to the dealer broken if you want but they're just going to take off the price of the repair in what they offer you. You're buying a transmission regardless, might as well get a good one and then the STi starts to look less appealing. That's where I'm coming from. Course, we're all emotional about cars (myself included) and it seems you've made up your mind so good luck! I'm sure you'll enjoy the STi.
The STi does have a lot of stuff like adjustable headlights, DCCD, the cooler dash, the better heads, the slightly stronger bottom, the BBS wheels, the brembos, etc. You are getting a lot for your money I agree.
2015 STi: Still Stock
04 STi, 04 WRX: SOLD