If I pay a loan off completely, can I deduct the wire fee? 

Then the remaining 70% I deduct repair cost and fees.

Our lease states: "DEDUCTIONS.

@Tyrond Duplantier Jr. if the loan falls under conforming agency loan (FNMA or FHMLC) then you should be eligible for Delayed Financing.  

A tax deduction is only worth 25% or so of the cost.

But then I started to wonder if this would have implications on the tax deduction of our primary residence mortgage?

So if your actual profit is $180k (often what people consider profit isn't true taxable gain) then your income is now $180k (Give or take for deductions/credits)  for the year- and your gain will be based on that accordingly. 

It seems better to buy the property and have them rent - for depreciation, repairs as deductible etc.

(Yes, the new tax law limits you on how much you can deduct, so please check with your CPA.)Option #2 you are an investor. 

@Adam Kerr those costs would be deducted from gross revenue to determine the Net Operating Income (NOI), then you divide by the cap rate to determine the approxiamte value.