I would avoid any Equinox/Terrain especially if it has the 2.4 4 cyl DI engine. The 2010-2013 2.4 engines had an issue with high oil consumption due to premature wear of the oil control rings.
I have a 2013 Equinox since new. At 42k miles the engine was using a quart of oil every 1500 miles. The pistons, rings, and a stretched timing chain were replaced under warranty. Before the rebuild, oil changes were every 4-5k, Dexos oil was used, and I never let the oil level get low. It has 70k miles and so far it hasn’t had any further issues. I would not buy one of these vehicle used.
Ed B.