I think that fittings are more useful if you're experiencing pain, if you're not... I'm not so sure. Things like saddle height and reach are easy to setup yourself, then saddle to bar drop is more a matter of preference, flexibility, and form. Having someone look at you while on the bike can go a long way to pointing out problems in form.

Anyway, for the price, I think that you're getting a pretty good deal and it might be worth it. Provided he knows what he's doing, $80 for 2.5 hours is cheaper than anything around here. Everyone around here is $250 for 2-3 hours.

Just keep in mind, a lot of the fitting stuff is a bit of "voodoo." Basically, don't think of the fitting as gospel. Give it a shot, but don't be afraid to tweak things yourself after the fact. A lot of the adjustments that can be made on a bike are personal preference, and no one but you can tell you the "right" setting.