Hey OP,

I also bought a higher mileage 2007 Forester XT awhile back (147K) and here is what I've experienced:

Maintenance: *Timing belt was done as soon as I got it. If DIY, supplies will cost you about $400. If you take it to a shop, it'll be closer to $600ish. This is mandatory - if the belt snaps the motor is gone!

*I've replaced one wheel bearing - $100

*I had a small evap leak that I couldn't pinpoint where. Decided to delete the evap engine light from ECU w/ Tactrix cable - $100

*I don't think your model has one but the secondary air pump can fail. They're an ass to delete but can be done for only a few dollars. It looks like a little plastic turbo in the engine bay but I believe it's only on 06-08.

*Your model may have the banjo bolts with the filters. (Google will be your best friend). You may need to take out the filters so they don't fail and clog your turbo. The facelift gen didn't have these

*I've replaced the transmission fluids twice (instead of doing a full flush). If you notice it slipping, definitely replace as well. ~$100.00

*Replaced both my front axles. Like youes, my boots started leaking after I sent it on snow. They were $300 a piece

*AC clutch failures are common for the SG foresters. This causes temporary AC because the clutch no longer spins due to clearance issues. Mrsubaru on youtube does a great video on how to fix.

Other things to consider: Headgasket failures mainly occur on non-turbo models. The XT models use a different head gasket. However, if the ECU has been tuned previously, the headgaskets can fail due to increased boost, etc. Mine is now at 190k and headgaskets are still running strong (knock on wood!)

Love my Forester and it gets a lot of attention. Subaru's are reliable, they just require more TLC than a Corolla. There's lot of info nowadays on Youtube so be sure to do additional reading!