I’ve read some of the posts on this topic but am wondering if I should unload it while mechanically good. 155k miles and has been the best car for reliability ever. In 15 plus years, fixed A/C and a rear brake line. Body is mostly very good, couple small dings and minimal rust. What’s it realistically worth? By winter, I’ll need the next set of brakes and tires, 12v battery etc. It passes inspection ok. If anything breaks, it’ll add a couple thousand. So it’s conceivable that I’ll dump 5k into it within a year. Should I be afraid of it? Too old to do my own work so everything is long price. What if I could get $5k for it, plus $4k off a used later year Prime and get a much newer car for a net $10k? if anything major breaks, afraid it’ll be a boat anchor. Right now, best car ever.
Out here on the West Coast people are still getting $10K or higher for 2010 in your condition... If you wanted to take a vacation out here, the extra money you'd make selling it would more than pay for the trip. Of course that's assuming you've done everything possible to prevent corrosion from salt on the roads.
you're at a high risk point. have you ever cleaned the egr circuit? potential failures: head gasket $2-8,000., brake actuator $3-4,000., battery $3-4,000. here's one for sale here:2010-toyota-prius-iii.255060
As someone who consistently gets more than a decade out of every car I own, it pains me to have to agree with you. I'd disagree if it was Gen2 Prius or a Gen4 Prius, but not a Gen3.
This guy in Oklahoma is rebuilding Gen3 engines and getting way more power and reliability out of them and if I ever find a good price on a Gen3 I'll put one of his engines in becuase his prices are super affordable: https://www.instagram.com/skimmilkhybrid/ But in OPs case, being older and no longer doing DIY, that would be more trouble than selling before putting more money into it.
Since you live in the Rust-belt, 15 years is all that you can expect from any car. Sell it as fast as you can before something else goes wrong with it.