Gen 2 or Gen 3?

Hey all, sorry if this has been asked before, but I'd love some fresh answers anyway.

I am in the market for a used car. I am pretty set on a Prius. I'd love to find a Prius for under $7,000 and 150K miles or less on it. This puts the Gen2 within reach and a few Gen3's (mostly 2010s and 11s). I am trying to sell my current vehicle and that will determine my budget. I am hoping to get ~$8,500 for it. I then plan on setting aside $1,000+ of whatever I make to start a fund for a refurbished HV battery for whatever I get.

My question is, should I just stick with looking at Gen2's (2007-09), or try to get a Gen3 (likely a 2010 or 11).

Generally I know newer is better, but I feel like I have come across more complaints on the Gen3s, especially with expensive repairs like a blown head gasket. Also a replacement battery is more expensive for a Gen3 (why is that, btw?). I think gen3's look cooler, but I am not as into looks as I am reliability.

Those things make me lean toward a Gen2, but I want to know if my concerns really are valid and if getting a 10+ yr old car is smart.

Thoughts?