I’d offer $6500 and see if they’ll take that… still not too bad for a 2010 RX (assume it’s FWD) AWD will have more $$$ expenses like tires etc. Heck, if it breaks you can WALK your commute
200k miles is a lot of mileage regardless of the manufacturer IMO. The primary parts of a powertrain could very well be solid (especially in a Toyota example) but everything else has still endured 200k worth of wear/tear. Not a dice roll that I would recommend, unless the entry price was stupid low.
Typical Toyota “reliability”: 06 has had a HV battery and Cat replaced, 09 had inverter pump, good chance either will need an ECM - a friend just had to replace on their contemporary well maintained/low mile gen2 prius that just had paint fixed under recall, ate another 12v battery while Cat was being replaced. But agree I’d take a lower mileage Prius that’s had much of the problems fixed than a 200k RX that needs another 100k service and mechanicals are getting up there.
It still had electronics: telematics module (even if network is ran on is shut down), infotainment screen (non-standard size/shape), a couple dozen “computers” (really “chips”, microcontrollers we heard so much about during shortages). Not especially unreliable but 14k/yr average for 14 years is a rough life.
Instead of Prius, just get a non hybrid corolla or camry. No matter how reliable Toyotas are, the HV battery is going to go some time after 100k miles. Replacing the battery will cost thousands.
Talk to your independent mechanic. If you don’t have one, talk to two about your needs and what they recommend. The hidden discount of “oh that car is easy to work on” is very underrated.
Beaters should be cheap. At $8500 you are close to the range of where you could buy a sub 8yr/75k mile Altima or Focus and throw on a Route 66 warranty for sub $1,500 and be covered for most repairs for 5 years / until 100k whichever comes first.
Also, consider your threshold for carrying collision coverage on the vehicle vs self-insuring. My definition of a beater is I will self insure it for any body damage that is my fault. E.g. would you pay $1000/yr for collision on a vehicle worth $3K? - probably not worth it.
Beaters you really have to follow your head and not your heart, if you wish to place a wise bet. Beaters are always a gamble to some degree. Your vision has blurred because you want to drive a Lexus.