You would be wise to get a proper strata legal search (including minutes of meetings to see if there are upcoming problems and ongoing issues between neighbours). This isn't a bad thing – buy a house in a street and you have no idea how your neighbours are behaving.
You will want a proper building survey done – just as you would if you were buying a house. Don't depend on the Owners Corporation to have fixed everything, even if they are legally obliged to do so.
I was just hearing today about a guy who skipped the building survey only to discover the previous owners had discovered concrete cancer and quietly sold up before the issue was ever minuted. A building inspector would have picked up on that immediately.
How much does it cost? How long is a piece of string and how much value do you place on peace of mind?
Apart from the structural stuff and the EC minutes, your search professionals should make sure there is enough in the sinking fund and there are no big ticket bills on the horizon. They might also check for lifestyle issues that are impending – if you have a dog and a building is about to go pet-free, you need to know about it.
And you want to look at the levies and ask yourself how you will be placed in five years when they have gone up 25 percent (or wherever CPI takes them) but your income may even have gone down. If that's an issue, look for a building with fewer facilities and therefore lower levies.
Good luck and stop worrying – this could turn out to be the best move you ever made.