Never owned a Prius what to look for ?

welcome!

it's good that you are doing due diligence before jumping in. a couple thoughts:

it is a bad time to buy cars, so expect to pay more than you would like for a good one.

hybrids are different beasts, and you want to learn as much as possible before buying.

what are your diy skills? if you are going to depend on someone else for major repairs, try to find a private hybrid mechanic before you buy. dealers charge a fortune and do a lot of scamming.
looking for a mechanic when you need one can lead to poor decision making.
as to your questions:
1) if you can, take a test drive in a new one, so you know what it should sound and feel like.
hybrids make a lot of funny noises that you don't hear in a regular car, but are normal due to all the systems that are operating with the car on and with it off.

2) learn how to reset the average mpg meter on each generation prius you will be looking at. there are 3 significant generations: gen 2, 2004-2009. gen 3, 2010-2015, gen 4 2016-2022. gen 5 comes next year. reset the mpg meter before the test drive, then take it for a good long drive over varied conditions to get a good idea what mpg's it is returning.

3) acoid gen 3 if you can, but if that is your price range, be aware of several significant issues such as egr circuit clogging, blown head gaskets, failing inverters and brake master cylinders. as well for the potential for a new hybrid battery.
each has a large repair cost, especially if you can't diy, like replacing a blown engine.

4) as to the battery charge level, it means nothing with the car sitting. when you are driving, depending on conditions, it should hover near the middle most of the time. sometimes it will drop to two bars, and sometimes it will fill all the way. completely normal. but if you see it rapidly fluctuating high/low/high/low, etc., that means the battery capacity is very poor, and it will need to be replaced soon.
a new battery is around $2,000. plus installation, which can vary greatly.

all the best!

 

Battery bar means nothing. Its a small high voltage battery that might run the car 1/2 mile at 20 mph. It will charge and discharge fast and that is usually ok. Determining if the $2000 battery is good is harder. Best to assume it will need replacing in a year or two just because its ten years old.

This generation 3 is known for oil consumption, head gasket failures, blown engines, bad $2500 brake boosters, inverters that can strand you with no warning, etc. They are not good used cars to buy to save money on gas. Because you could end up spending $10k on repairs in the next two or three years.

Most mechanics can't fix them so you may end up at a dealer paying $150 an hour labor on top of high priced parts. There are options for advanced diyers but they are not easy. Swapping an engine or component level repair of the battery in your garage is not for everyone.

Buy a conventional Civic or Corolla and thank me later.

 

"a Prius" can cover nearly a quarter century of cars ranging from a clapped out 2001 with lunar mileage to a Prime, which is a PHEV.

If you're looking at a "wireless" Prius and you're worried about the battery you may want to consider a Civic or a Corolla instead.
It's not that Priuses are bad cars.
If fact...they're really very GOOD cars....HOWEVER!!!!
(comma!)
If you're buying a used car in the Year of our Lord 2022, you're already paying top dollar, and you always have to ask yourself:
"Why did somebody SELL this beautiful little creme puff???"

As our beloved President would be wont to say:
"Here's the deal...."

A Prius is a Hybrid.
All this really means in real life is that it has a two batteries instead of one, regenerative brakes, an inverter, motor-generators and a few other bits IN ADDITION to all of the other stuff that can break on a "normal car."
Mostly, that stuff doesn't break, which is the BEAUTY of Prius ownership.
The BANE of Prius ownership is that less-than-honest dealers and mechanics can scare the bejeebers out of hybrid owners making them think that you have to have a Master's Degree in Nuclear Medicine to wotk on these cars.

Spoiler Alert!!!
You don't.

Since they've been around for nearly a quarter century, we pretty much know that the batteries (meaning the "traction" or high voltage batteries) last about 10 years or 150,000 miles without failing.
That pretty much also applies for the inverters, motor-generators, power-split devices, etc...

That informs the wise purchaser that in a car that is less than 10 years old or with fewer than 150,000 miles that the hybrid bits (including the "battery") is pretty much a non-issue.

Besides:
CARB warranty.

ALL OF THE OTHER STUFF?
Is the same as it is with any other small, egg-shaped 4-5 pax front wheel drive car.

Years.
Mileage.
Options.

You want them all small UNLESS you're willing to leverage a little SWEAT EQUITY to save you some money.
If your idea of vehicle maintenance (note! this is DIFFERENT than vehicle REPAIR!!) is to toss the key fob at somebody at a dealership and hope that they will be merciful with you, then I would recommend a different company's car.

MY mileage!
YOURS will vary.

Best of luck!

Specific questions about Specific models happily addressed...

 

He did ask about a specific model and he included the miles. $12k for a 10 year old Prius with 128k miles. Concerned about the battery gauge being low.

My response in a nutshell

 

Are you buying from a private party or a dealer? Either way, get it in writing weather it has the original hybrid battery or not. If not, was it replaced with an original Toyota battery or a "reconditioned" one. If reconditioned, either don't buy it or offer $3,000 less. If from a dealer and on original battery, buy only if they will agree to replace with a Toyota battery if the original on fails within next 2 years.

I agree with Bisco that you probably shouldn't buy without having DIY maintenance skills.

 

Well, IN ADDITION to much of that other stuff, but MINUS: starters, alternators, transmissions that shift (or vary ratios mechanically), clutches.

... which just happen to be among the things I was most likely to have to replace or repair in previous vehicles.

 

Will you have a convenient set-up for charging?

Does this particular car have dashboard trouble, or did you just read about it on others?

 

that's a bad combo meter. big installation job, a thousand bucks at a dealer. you can buy a remanufactured one for a few hundred, if you want to tackle removing the whole dashboard.

check the 12 volt health first though, that can also cause the issue

 

2012 plug in is not a prime. it is called a pip (plug in prius)
gets around 10 miles of ev on a full charge. ask the owner to charge it up before going for a test drive. see how many miles you can go on electric before the gas engine fires up. try it around 30mph back streets.
keep in mind, that's a big battery, and big money if it needs to be replaced. ignore what i said in my last sentence above.