Your question is overbroad. There's a huge difference between downtown Charlotte, NC and Sticksville, TN.
Perhaps you could expound on what, specifically, you are considering.
How could we possibly know what kinds of unexpected expenses you might be facing in a given, hypothetical property?
There might be elephants in the hall closet, wormholes in the crawlspace, aliens in the well, unobtanium contamination in the bathroom, armed gunmen in the garage and coffee grounds in the woodstove, just to name a few.