In my opinion that is a very fair price, probably could buy it and then sell it for $15+K at one of the large consignment dealers.
Is pretty, and I hate to say this, for a '70. Green one in Canada sold recently and this & that one were probably the two nicest looking '70's I've ever seen.
I agree about the '70 Rivs....the front end is just.....ummmmmm.....weird. But I wouldn't kick this one out of bed for eating crackers.
The 1970 Riv is the step-child in the Riviera world. My family has owned a couple over the years and I don't mind the looks of them so much. This looks like a nice, clean example. I like the color combo on this one but, I gotta say, these cars definitely look much better with the sweep-spear moldings on them. It kinda breaks up the bulky look of the profile of the car. JMHO....
Price reduced to $8500: https://portland.craigslist.org/clc/cto/d/1970-buick-riviera-1/6415488787.html
Ha.... Can I move to your place got an extra room available... Reason el Camino sold was we had too much stuff...now I only have 7cars and 2 Harley's