I am considering buying an 88 Turbo Coupe 5 speed,121,000 miles

Nothing beats an 'in-person' inspection! IF it is a car you WANT , then you will find a way to put up with any 'problems' that occur! Make sure it gets at LEAST an hour of run-time , including a good drive on an interstate (maybe offer to put some gas in it, if they have nothing to hide m, they shouldn't have a problem. Even let them do the driving- but make sure they give you a good demonstration of its condition!Good luck! If you get it enjoy it!