is a honda odyessey with 122,000 miles safe to buy

Depends on what they are asking for it. go to KBB.Com or edmunds.com that will give you the value of the vehcial. Who rated it the dealership?

Look in the glovebox for the +checked off maintenance list...including timing belt axles and oils...windshield wipers...tires and all items on the schedule...if not then you're takin' chances~...also look underhood for evidence of a prior overheat and the coolant for the presence of rust/tap water~

Remember it is 8 years old with over 100,000 on it Honda makes a good car but I get liery of any thing over that milage. Like roy said check all the maintenance records and may check carfax

if you're on the timing belt and tensioner they'll last for a spell~ most people are like "it runs, why bother"...but until it snaps into shreds and gets towed into the shop and it's your job to put a new one on there and cross your fingers that it snapped without subsequent damage...the customer drives away with the new components installed and nare ye a thank ye from the Berkeley crowd~