is it risky buying a travel trailer that is 8 years old

Hee, hee, hee......look how old mine is...

I would guess the most risk in the transaction is trusting the dealer to do an adequate job of inspection. If you're new to RV's it may be in your best interest to hire an independent inspector to examine for water damage. Everything else in a used TT pales in comparison to water damage for expensive repair.