The other thing about a short time horizon, is even if it's cashflow neutral, you are really gambling on the real estate market to either stay flat or go up, during you investment period. Honestly, that's not a wise gamble for most people today, unless you can get into a screaming good deal, that has some down market safety.
The reason a cashflow neutral position is critical for an investor, is that it allows you to "ride out" a down market, until a suitable exit point is found. Your money is tied up in the property, but at least it doesn't cost you anything to own.
Ok, no joking!!! No, keep in mind that there are many expenses to buying and selling real estate. Over very long periods of time, ordinarily say five years, given our present uncertainty, probably more like 10 years or more, buying is better than renting.
But over such a short period of time, it would be extremely unlikley that the home could possibly go up at all, let alone enough to justify the expenses of selling it 18 months later.