158k miles on a 2007 Prius?

Age and internal heat are the killers of the big battery, Kansas won't cause much internal heat as you never go up or down much.
The transaxle gets suspended metals which short out the motors, ($5000) it you drain and fill the ATF WS (about $100) all the suspended metals are cleaned out,
Never jumpstart other cars and try not to jumpstart your car, doing so badly is a huge bill ($4000) for a new inverter.

 

At roughly 9 model years old, and 150k the most obvious concern would be HV battery.
Unfortunately, I don't think there really is a good way to determine whether one is going to fail or not.
It could fail tomorrow, or give you 100,000 more miles and 6 years...who knows.

But my approach if I was buying a Prius in that age range and mileage would be to hopefully be doing so with the knowledge that HV battery failure is possible and the resources set aside to deal with that problem if it does happen.
That's roughly a $3000 replacement cost, unless you go the more dubious rebuilt/remanufactured route, and that has mixed results, and IMO is not the best way to go.

Don't mean to scare you, as there are many that get significantly greater life from their HV batteries. It is possible you could NOT have a problem with it for a very long time. BUT...I think any time past HV battery warranty on a Prius and that becomes an issue in which one needs to be prepared to deal with at possibly any time.

As with any vehicle, in that age and mileage range, other problems such as engine, transmission etc can also manifest. But I think usually those give more warning and are more easily detected and predictable. Being a chemistry based piece of equipment, HV battery failure can be pretty sudden and seemingly instantaneous and IMO much more difficult to predict.

 

welcome! have you considered a corolla, yaris, civic, cruze, mazda, hyundai?