If you're really leaning towards getting a new one and it's worth anything at all in the Kelly blue book, I'd say go for it.
I was trying to eek my way through the Spring (and maybe Summer) on my 145K mile Subaru. It was running absolutely fine -- slower on the pickup, maybe a little louder, but sound and safe.
A few weeks ago the headgasket blew -- it went from $2500 Kelly blue book to needing $2900 worth of repairs. They made a token offer for it, but had I turned it in the week before I would have made out at least a thousand ahead, and probably more towards the new car I was basically planning on soon anyway.
I'm not bitter -- if I'd gotten another 6 months out of it it would have been worth it, but...
I've BOUGHT Subarus with more miles on them than that. I drove my first one to 239,000 and it was still running good, but starting to get some mechanical things that needed to be replaced like the tie rods. I still regret getting rid of it because the gas mileage was better than on the ones I've had since. I now have a 92 Legacy that my son drives and a 97 Outback that I drive. Both are in the 170,000 range and doing great.
$2900 is WAY too much for a headgasket! Is that at a dealer? I've had them done and can't recall the exact amount, but it was nothing like that. I want to say in the $600 range. I have a terrific mechanic that I've used for years. He worked at a dealer when I met him and did other work in his garage at night and on weekends. I found him by asking around. He was recommended by someone I knew that worked at an auto parts store. Later on the dealership closed and he opened his own shop.
Sheila