One of those 5 moved to one of our larger houses that came available, and all the rest bought a house.Vacancy hasn't really been very high - 6 weeks in 4.5 years - but the annoyance factor is huge.Other than that, I think what has cost us the most is taking too much time getting the house ready to rent when we first purchase it.

You will also want to factor in property taxes as part of the annual cost and closing costs with the purchase.

Make sure to factor in your cap ex, maintenance, fixup costs etc.... and if it hits your cash on cash return then why not? 

The answer depends on so many factors including but not limited to: age, risk tolerance, job type, job income, job stability, long-term goals, education, type of market you will invest in, current savings rate, cash reserves, etc, etc. 

You could always refi it after you move in, if it made sense to do so after you factored in the refi costs.

Are those adjustments that you listed already factored into the rates presented or are those on top?  

Also, the climate is a big factor.

Also depends on other factors like down payment, lender's loan requirements, after market loan buyers, etc., etc. 

I am sure there may be other factors that I don't know about that contribute to your dilemma but the definition of high crime area is very vague.If it was me I would give the neighborhood a try. 

It all depends on the area and hassle factor your looking to put up with.