100k isn't a magical number, except in some people's perceptions. Buy the best looked after car that your budget can push to, irrelevant of the mileage. I've run several cars well past 100k, with correct maintenance and the right attitude to car care it's just a number on the dash.
Agree that 100K isn't a magic number, at least where the engine is concerned. If I were to be looking at a car of that age I'd be taking a close look at the maintenance history. Not just regular servicing, although this is important. I'd be looking for a clutch change on a manual car (or be budgeting for it), I'd be taking a close look at the suspension bushes, checking whether I'm in for a timing belt change, I'd be listening for wheel bearing noises, the list goes on...
I'm not saying don't do it, just go in with open eyes, check the prospective purchase thoroughly and a car with > 100K miles can be a good purchase. Some years ago I drove a well maintained 996 Carrera 4S Coupe with over 200K, it felt almost as good as the 60K cherished Carrera 4S Cab I had at the time... but the guy had spent money on it, rebushing the suspension, new clutch, new rads & air con condensors, new dampers and so on but original engine and gearbox... mind you my I'd spent plenty maintaining my 4S too
The thing is to find an example of what you're looking for that's been looked after...