Replace engine/hybrid battery situation question/advice

I bought my 2007 prius in 2010 as a 2-year lease return in great condition and have generally kept up with maintenace (overdue for a radiator flush, but otherwise on schedule). A few weeks ago it died on the highway in another state and my only option was their localish dealer. The triangle and check engine lights had come on earlier in the day, so I'd pulled off (one state earlier) and had a shop check for codes, but they said they didn't see anything wrong, eventually deciding that I must have a bad coolant sensor, but said that since my coolant level looked good I could drive the rest of the way to GA and get it fixed after I got there. Asked them to check my hybrid battery and they said it looked great, 15.8 and balanced. An hour later it died in TN. All lights came on, lost power and heat, and it died before I could do more than pull to the shoulder. Had it towed off the highway to a motel so I could unload my animals and look up the nearest place to bring it in the morning. When the tow guy turned it on we saw the signature white smoke of the head gasket and smelled the burning antifreeze. I rented a car to keep going to GA and had it towed to the nearby dealership on the advice of the tow guy the night before. The dealership said the engine was toast and needed to be replaced, and quoted me $6700 for a used engine with 131k miles and a 1-year warranty. Yes, more than the car is worth, but I eventually decided to do it since at least I knew everything else had been maintained and the battery was in good shape. They said it would be ready after the holidays.

Shortly before it was supposed to be ready I called to confirm my pickup date (by then I'd gone back to Ohio - rented a car back to TN and the dealer gave me a loaner to use while they worked on it). The new engine had thrown a check engine light and they needed more time to troubleshoot it. They said I could just keep the loaner until they were ready. They called two weeks later and said it was ready, so I drove down yesterday to pick it up and return the loaner. When I got there it was a little more than they'd quoted, and their tax rate is high, but when I brought it up he knocked off a couple hundred to get back to 6700 + tax. When I got in the car and pressed start, all the lights came on and it shuddered.

Went back in, he said it drove fine the day before, and they pulled it back in to look, thinking maybe there was a loose wire. Came back half an hour later and said it was a bad camshaft sensor, they'd replace it for free and it would take another half hour. Took a little longer than that, but then he came back and said there were still error lights and they would need more time, so they would send me back home in the loaner and arrange to deliver the car when it was done. (so I drove 14 hours yesterday for nothing)

Now they say the issue is the hybrid battery. That one cell is dead and another is low. P0A0F and P0A80. They said they could put in a greentec battery with a 1-year warranty for 2100. At this point, I'm inching toward how much I paid for the barely used car back in 2010 (13k) but the $7260 I paid to put in a new engine isn't something I can get back. Honestly if I'd realized the TN tax rate I'd probably have said no to the engine -- I had decided on 7k as my upper limit for having them do the work and the convenience of not having to daisy chain tows to get it somewhere else for cheaper work. But here I am. There was some not-quite-right communication over the phone when I was asking about the used engine they were going to buy. I thought the engine was 4k, but 5k is what they charged for labor (!) and the actual charge for the engine on the invoice was only 2497 (infuriating but I wasn't together enough at the time to ask for the estimate to be broken down in writing and emailed to me).

So here I am, hemorrhaging money on car three states away, trying to figure out if I should save it and hope there nothing more major than the usual anticipated occasional replacement things for the next 100k miles, or if i should give up. These seem to be my options; which do you think is the best idea? (all prices are base, so would have about 10% tax added)

• Dealer orders the 1-yr refurb battery from greentec (all cells 80% or higher) and installs it, their original suggestion. $2100
• I order a new cell (panasonic cylindrical) 4-year warranty battery from Greentek and Greentec installs it in the parking lot. $2600. (Or they'd do the same with a 2-yr warranty refurb, all cells at 90% or higher, $2100)
• I order an OEM from greenbeans and they install it in parking lot. $3099
• I admit the 7260 was a really bad decision that I made without getting enough information in writing (because I was so traumatized by breaking down at night in the middle of nowhere when it was below freezing and I had three animals in the car and the whole reason for the trip was my dang birthday) and stop trying to save my beloved gen 2. See if I can sell it at a loss somewhere within 200 miles of the dealer that wants it for parts and have AAA tow it there, then go looking for a different car to buy.

What do you recommend?

Note: Yes, I know I should have gotten more info before saying yes the first time. I also should have had a scanner with me. I should have daisy-chained tows to get it to GA where my brother has mechanic friends. I should have done a lot of things. It was my first road trip in several years due to long covid and I wasn't being smart, I admit it!!

 

Didn't realize there was a moderation delay. In the meantime I asked some people for advice including my mechanic brother, and I went ahead and ordered the OEM.