Ruel, you may be able to find a contractor that will walk the property and give you an estimate, but it may be tough, sounds like the Realtor gave you some idea of the rehab cost and depending on how much you trust him, sounds like he may have told you a number that may get you the house. so 205K plus say 65K for rehab puts you at 270K. you have about 10K in purchase closing costs about 22K in closing at sell, if your intention is to flip the property ( if sold for 320K) so now you are in for 302K plus holding costs, maybe another 10K, so 312K. you could make 8K in profit, if you sell at 320K. i am guessing this is a foreclosure being that you said that not having a home inspection would make a difference with the bank in selling it, because most lending banks would want a home inspection. you can have an inspection for your own piece of mind but still waive the inspection.

There are deals in every area, all depends on your preferences.  

@Brandon Metzler - depending on the wording in your current Contract/Agreement, you "may" be able to simply Assign the contract to another buyer.

Also, depending on how the value of the property increased by adding that third unit, plus natural appreciation and paying down on the principal, you could look at refinancing out of the FHA loan to get rid of PMI.

There are limits, etc or special requirements depending upon how many replacement properties you identify.

It all depends on what your goals are. 

I think it depends on the language in the lease.

I'd say it depends on the deal and your market.

It might not be that simple depending on the context of the neighborhood, and your neighbors.

And that largely depends on the need for a certain type of transport airplane.