I have to agree as my low milage '01 is popping stupid little problems all the time. My CPO expires in November and I'm trying to work out what to do with it. Just had water pump/thermostat/belts done 3 weeks ago and then it blew a LKM. That's about $3K of parts/labor in 3 weeks that the CPO paid. Not a pleasent thought if you are just about to buy a high milage model. I just topped 42K this week! In the 12K miles/22 months we have owned it you can also figure in balljoints/links etc. $1600 -$2000 CPO, Cam Position Sensor $200, Door Handle (fell off) $100, Door Lock Actuator $500 CPO, CV Joint Boots $300. You could be looking at any or all of these in the near future as many of these things (like ball joints) seem to go every 15K miles!
LEASE or at least buy a CPO as it will cover some of the bigger items. Some of my out of pocket expenses were mitigated as I have my own mechanic who charges a very low hourly rate compared to dealership.