Got any pics of the Blaster? Personally, Id make the trade. Stock-for-stock, you'll have more fun on a Blaster IMO. I got to ride a TTR a couple years ago and got bored with it rather quickly. Good bike, but not my thing. The Blaster is a lot more exciting to ride and has way more mod potential than does the TTR, especially when it comes to improving engine power output.
A 2-valve, SOHC 4-stroke engine is rather limited, but you can poke, stroke, pipe, carb, and BBK a Blaster engine to twice or more its stock HP.
Like any trade, be sure to do your usual checks and inspect the bike well before trading. That dead rear brake caliper is no big deal to fix or replace, but weak compression or piston slap (which you can't detect with just a visual check) will cost a lot more to fix if you wind up with said issues in a trade bike.