2013 Subaru Legacy Premium at 95k miles - Worth the buy?

I would not worry about that bit of oil at the filter. The oil change guy probably did not wipe up the oil when the filter was changed. Your plan to have a mechanic check it out is good and your concern about the CVT is valid.

Yup...except: check to be sure that the seepage doesn't emanate from a seam on the aluminum large front engine cam cover, as this is a horrendous (10hr repair)! But more likely it's spillage.... You are at. fairly strong risk for both needing a CVT valve body solenoid ($1k all in) or an entire used CVT, which is difficult to source used as 2013 is all alone for swapping. Hence expect to pay $1.5-2.2k PLUS $600 labor to replace with another used one. If you're doing that grab the old valve body on the way to the metal recycler. A safe course might be to put aside $1-2k for CVT issues ongoing. All these Subies eat wheel bearings, so expect to need them eventually too...especially the rear. ($250 each corner, as needed). "Servicing" the old CVT is useless, as the old fluid draining out looks just like the new, and it's a biut tricky to get the level correct...which is more important than changing it! The sturdy new (2013) DOHC 2.5i uses iridium spark plugs, so don't chase them until the 10-12 yr or 200k mark, let's say. Your front serpentine might start chirping; if so, replace with the 1/2" shorter one to accommodate the eventual stretching. Brakes and exhaust are easy, and the gas struts usually hold up well. Being a lower Legacy, you don't require the thicker STi rear antiswaybar needed on the taller OBs. Handling WILL be better with UHP H or V good rubber, as the excellent steering warrants it. I sold quite a few 2013-2014 Legs/OBs years ago, and only one client (my daughter!) ate the CVT, so relax and realize you're rolling pretty favorable dice. Good luck.