While I don't own an Aircore, I have flown one and it is quite heavy and may not be the best choice for a First trainer.
If you like the idea of the Aircore being nearly indestructable, and want to build, take a look at this link:
http://www.spadtothebone.com/SPAD/Debonair
The "Deb" is build along the same lines as Aircore wherein it is built with PVC (gutter) pipe and corrogated plastic (coro). The Deb should be lighter than the Aircore which will give you gentler flight characteristics and at a fraction of the cost. To build the Deb should cost you less than $20 and is reported to fly even with a LA40 on the nose.
Check out the Deb before you decide. If you have any questions about the Deb, jump on the SPAD forum at
http://www.rccombat.com/forum/forum....rplane+Designs
A great bunch of guys (and a few gals) that are more than happy to answer any questions you might have about the Deb or SPAD (Simple Plastic Airplane Design) in general.
Good Luck