So I'm looking at a 2008 Subaru legacy for my grandma and was wondering how long they last it has 188K miles do a lot of problems happen around then they are asking $6K would this be a bad car

That car will need head gaskets and a new timing belt soon if these repairs have not been done fairly recently.

An '08 at 188k either is bleeding badly (check it out!) or has already had gaskets replaced. No difficult to assess. You can inspect the t-belt too, but that was replaced with the HG. Leave the water pump alone, btw. HOWEVER, the AVERAGE 8 yr old OB will have a laundry list of needs that may prove too demanding for a senior citizen who doesn't want to fool with it. I am ROUTINELY replacing nearly all wheel bearings, axles, swaybar links and bushings, rear exhausts, as well the normal brake rotors, plugs (use iridium), belts and filters. But I must tell you that 80+% of the "golden era" '06-'09 OBs I assess I rule out because costs of prepping to excellent state are too high. It's getting really hard for me to find good 'uns. And my compadres servicing early adopters of the next gen (2010+) are already chagrinned at how cheaply made the new Toyobarus are, using soft weak steel stampings that aren't rustproofed, etc. Subiie really dropped the ball here, and are strictly building too a price point. Sigh.... IF this '08 OB candidate has dry HGs, perfect AT with clean fluid (rare), good WBs, not leaking at the rear y-pipe ($500-700 if muffler flanges are too rusted to reuse), and good axles and suspension then maybe it's worth a shot. Even so, she'll call you periodically to chase the $200-300 "popcorn" that will need attention randomly. Indeed, old Subies love-hate cars depending upon luck and to some extent keeping clean fluids in them from either wearing out (AT) or bleeding out (oil, coolant). I'd say there's statistically about a 10% chance that this chariot will make her happy over its death curve. BE CAREFUL!

Excuse the minor misspellings above. Too badd there's no edit function....