Investing is a business.

Purchasing a primary residence may be emotional, but investing is about numbers. In your primary residence, you might be concerned about repairs and what is too much. In your investments, think about the income the property will generate and figure what percent of that will need to be dedicated to repairs, maintenance and capital expenditures (major updates like roof/furnace/etc). All properties will need money put into them over time, so determine what the appropriate numbers are to make your deal work for you!