Ideally, you should base your property coverage limits on how much it would cost to rebuild your home. That's sometimes the house's current market price, but it could climb higher. You should consider insuring over market price if your house is older, you've got other structures on your property (like a shed or four-car garage), or construction costs in your area run high, for example.
There are also a few different ways your claim will be settled depending on your policy. Actual Cash Value will reimburse you for the replacement cost minus any depreciation. Because the cost can vary so much over time when it comes to property, this kind of policy could mean the limit on your coverage ends up coming in significantly below the cost to repair or even rebuild your home.