My buddy had all kinds of fords and gmc's diesels and they all had 2 fuel filters (spends like 70-80 bucks in one change).
I only changed one filter up to 70k miles, at almost every oil change and it only cost $20.
Is that it? Or is there another filter?

 

Yep there's only 1. I've owned several powerstrokes over the years and they have 1 under the hood and one on the driver side frame rail. It costed 60-70 bucks to replace them both. Thank God the dodge only has one and costs under 20 bucks. More reason to change it more often.

 

how hard is it to change the fuel filter on the '07 6.7?

Where is it even located?

 

That's what I tought. I change mine every oil change and it can't be easier to do it. Very nice design on these Cummins!
As far as 6.7's I'm assuming the filter is in the same location: hood compartment driver's side, towards the back, you should see a black canister with a yellow plastic lever on bottom (to empty). If not, do a search on the forums.