then hopefully, if the time comes for you part ways, you can garner a good price. however, it will still only be worth book value. if anyone wishes to pay more, than so be it. meaning, the car is worth, whatever someone will pay for it.
i remember back in my wrenching days, those cars had stress cracks at the B pillar door sills, towards the rear of the sill. that being a T-top, i am not sure if the unibody is reinforced, like a convertible would have been, since so much roof is cut away. the door sills too, were prone to severe rusting. remember too that back in the day, there wasn't as good an anti-rust agent applied to the metal nor any good rust proofing.
at one GM dealership we had, (i worked at 2, on e chevy, one a buick) they sold "Rusty Jones", which claimed to prevent rusting and had some sort of limited lifetime guarantee. over the years, i had seen more camaro's and firebirds rotted out, as the Rusty Jones, actually trapped water inside, as the dummy that applied it either did not drill the application hole properly, nor plugged it up properly. door panel bottoms would rot out, cuz the Rusty Jones would plug up the drain holes in the bottoms of the doors. water would eventually seep out, but at the cost of eating away the insides of the doors.
i'd seriously consider taking the rocker panels off (you most likely have chromed or plastic ones) and the door panels and get in there really good with either a snake light/inspection camera to check for rust. repairs now will nearly guarantee a good resale later, or a longer life if you keep it.