What's the best way to fix my Gen 2's Hybrid battery?

My 2008 Gen 2 that is showing P0AA6 and P0A0D codes. The car has 149k miles, new tires, and a clean title, but since it's been sitting in the desert sun for 2 years without being driven, the 12v was dead, the paint's top surfaces have peeling clear coat, and the car is dirty inside - needs a detail.

I have someone who will come to my house (so I don't have to tow it) and replace the battery with a refurb for about 1500. I'm happy to invest that amount if it makes financial sense. I could do the job myself and save $250, but i don't have time.

The local toyota dealer will sell me a new one for 1775 plus tax.

I really don't want to spend much time on this car - i just want it gone, so I figure if I can get it running for the lowest price, that's best, and then I can sell it. Caveat: I have no idea if the gas generator is working well, or needs help. This was not my car, i'm helping a friend who doesn't remember the status of the engine when it was driving.

I don't know what this car is worth as it sits, or when it's fixed. Is it worth it to invest money in it? If so, what would you do regarding the hybrid battery replacement? What's the easiest, lowest-friction path?

Thanks.

 

A few pics of the clearcoat peeling.

 

Thank you, will do!