The Acrobatx will actually take a pretty decent beating... It's ranked as an intermediate kite, and was designed for a little abuse... Rods are pultruded, so it won't be as costly to replace anything if it does break.
If you're really keen on learning on something else less expensive first, you might look at the Cherry Bomb by New Tech... Around $50, it's a decent flier.
The key is, you really won't be able to do much on kites for under $80... For only $30 more than the Cherry Bomb, the Acrobatx is the first in it's price range that will allow you to do some of the higher end tricks, take some punishment, and not hurt your wallet too bad.