1. As many have already said, checkouts are standard. If you want to rent my stuff, I can come up with whatever rules I want in order for you to borrow it.
2. You knew (or should have known) the rental rate going in. So you can't complain about the $260/hour.
3. My big point here:
One of the first "real-world" lessons that every CFI learns, is that EVERYONE is a great pilot - in their own minds. It seems like every pilot I do a Flight Review with, when we're talking beforehand, might say "I'm a pretty good stick and rudder guy, but maybe my avionics knowledge is a little weak". And then of course, they can't land on centerline or hold their airspeed in a climb or whatever. EVERYONE's opinion is very high of themselves, so as a result I just plain don't believe their self-assessment - we will test it in the air and I'll make up my own mind.
Logbook fraud, and outright embellishing of experience happens, and more frequently than you think. So "I have 200 hours in a G1000" doesn't mean anything to me unless you can prove it.
I've found that the best pilots are the humble ones. The worst pilots are the ones that are deceiving themselves, and loudly brag to others.
I remember one example of a great pilot from my early instructing days. Now, I had about 1000 total hours, but only been a CFI for a few months. A guy shows up on the schedule for a rental checkout in a 172. We meet and he humbly says "I wasn't sure what all you needed to see, so I brought all my logbooks". Okay, I take a look. These things go back a ways - he flew helicopters, fixed wing, airline, corporate, just every kind of flying you can imagine. 30,000 hours or so. And here he is getting checked out in a 172 with a new CFI, me. He could have easily acted like the OP and bragged about all his experience, and how he shouldn't have needed a checkout, etc. But no, he did exactly the opposite.
He looked right at me and said "I know I have a lot of experience. But it's been a while since I've flown a 172. So just pretend I don't know anything, and just tell me what I need to do to be safe." We went and flew. It may have been a while since he flew a 172, but you wouldn't know it. Smooth on the controls, efficient in movements, no wasted energy. For the last landing we decide to make it a power-off 180, Commercial style. If I recall correctly, he even said he'd never done one like that. And as most CFIs know, power-off 180's usually involve a lot of slipping and S-turns and stretching the glide and all kind of tricks to try to make that spot the first time. This guy just flew a normal pattern, a little tighter but flaps at the same points as normal, smooth motions, speeds the same, no drama, no nothing, and put it exactly on the spot like he'd been practicing for a checkride.
That day I learned that the people who really have the skills, don't need to tell anyone - it will quickly become obvious.