2004 160k traction battery dead, sugestions...

A shop told me the traction battery is shot (bank #9).

A replacement (Toyota part) is $2588.97+$288.20 labor = $3108.86 with tax. It will have a 2yr/24k mile parts/labor warranty by the shop. Shop said that they could bring in used battery and recondition it, but that would only save me ~$500. They said I could try to repair cells and recondition for $1500, but given age and heat this battery has seen believe it would be unlike to be successful.

Background:
In March CE light went on and coded P1121 plus the whirring noises every few minutes. That is the coolant three-way valve. Research told me that it is not a must do repair, but of course the CE light no longer can tell me if anything else goes wrong.

In early July the car was not driven for 10 days. On return it started up fine, but after 5mi gave red-triangle. I avoided the problem and car remained unused. I did check a few times and the battery indicator went to 1 bar when left alone, but charged up to mid range with some light driving in neighborhood. Inverter coolant was moving fine as was ICE coolant. ICE coolant pump replaced several years ago.

Drove it to shop, by then the battery indicator stayed at one bar and it took ~20sec to get from 0 to 30mph, but once at 45mph it held it like cruise control was on.
Shop told me the above about the traction battery and that it also has codes P1121 as well as codes related to ABS system, but said that Toyota has extended warranty on the ABS and I should have Toyota repair ABS module under warranty.

The vehicle has all the expected wear of a 12yr old car - loose visor, dings, cracked taillight housing, etc.
Other maintenance needs include:
-Front tires getting old (front 6/32, but with dry cracking from heat, rear have 8/32)
-Front/rear shocks sagging, but not terrible.
-Transmission fluid is brown, replacement quoted $118

I am willing to put in the $3500 to repair, but wonder if that is dumb given age & mileage of car. I really don't want to buy a new car right now (bought a new truck a year ago) and figure I could get a couple more years out of it and get a bit in resale to get some of the battery replacement cost back. I view vehicle as a tool, not as a comfort or image.

One concern is the ABS - as by CE light was blocked by P1121 I don't know if this is new or if a symptom of bad traction battery and worse not sure if the extended Toyota warranty will cover it.

Suggestions?

 

It is not a Toyota dealer it is: Chandler Auto Repair 85226 | Nate's Next Gen Auto Care (480)699-0754 | Honda Repair in Chandler, AZ – Mechanic Auto Shop Theme
I live ~20mi from Camelback Toyota, it is where I bought my truck. It looks like they need the core back to get the price, but I can ask Nate if they can match or get it from them. That would be ~$400 less.
Nate told me that in his experience with a 12yr old battery that has spent its entire life in the hot Arizona desert conditions that they are often so many bad cells that by the time you replace them all you will be close to new battery price.

 

A bit more info. The codes that are being generated are:
Battery:
P0A80
P3019 - bank #9 weak
ABS:
C1242 - low/high voltage
C1256 - accumulator low pressure
C1259 - HV re-gen fault
C1310 - fault in hybrid HV system
Transmission:
P1121 - coolant valve (this has been generated since March-2016)
P1122 - coolant circuit low
P2318 - low voltage error

The shop reminded me that some of these codes under ABS/Trans may be because of the bad traction battery. The only code that AutoZone (i.e. not Toyota specific/detail codes) read in Mar-2016 was the P1121.

They also said that if I bring them a battery, they will install it and give me the old core then it is up to me to get the refund on the core from Toyota and that it gets shipped back to Japan for Toyota to inspect and it can take several weeks to get the $1350 back.