Opinions, there's a saying about them. I bought a 2005 RTX mid summer last year with 250 hours on it. We ran the ass off it till cool weather. I'm now in the process of replacing carbon ring, rebuilding impeller, and supercharger rebuild. Doing those things myself. If I get one, maybe two more seasons out of it without major issues I'll be out far less than depreciation on a new machine.
So, if you're buying two 04 for what you'd pay for one 08 or later, especially with what's really pretty low hours for that year machine, GO FOR IT!!