They are doing right by you. You can spend less. The 7.2 model is less than $500. But the 7.3 gets you to an aluminum fork instead of high-tensile steel. Frankly, I avoid anything with high-tensile steel in it. The 7.4 model gets you to a carbon fork, which many riders prefer due to lighter weight and -- I am told -- a propensity to absorb shocks from the pavement. Having nine-speeds on the 7.4 is a plus as well. Nothing wrong with eight speeds per se, but nine is more in the mainstream, and it's easy to find high-end nine-speed components should you end up with upgradeitis.

I wouldn't choose the 7.4 for mountain-bike singletrack style riding. But I'd ride it on a smooth dirt path, or a gravel path like a rails-to-trails type thing.

If you visit the hybrid forum here, I think you'll find many people in that forum who ride and like the Trek FX series.