I do not know anything about maintenance as I've not owned an aircraft yet so this should be taken cum grano salis. I can tell one thing about the 175. It's got the geared GO-300 engine. These engines are generally costlier to overhaul than direct drive ones and also have a lower TBO.
I had a short mental breakdown not long ago when I looked at buying an old clapped out Aero Commander with the GSO-480 engines. Granted, they're bigger and more complex, but the overhaul was quoted as $40.000 each, which is about $10.000 more than the direct drive equivalents.
It could be different with this geared Continental in the 175, but something you should look into.