Does the cost per sqft account for electric and plumbing? 

Insurance-  replacement costs.  

I'm looking at monthly cost to seller vs. anticipated rental income, purchase price relevant to the ARV of the area and interest rate, balloon, etc.

It will likely be cheaper than the cost of financing.

I already have some equity in the property after doing a complete rehab but I don't want to diminish my returns selling it after one year, paying for commissions/closing costs.

Here is an example of what it costs you to avoid professional advice.

It will cost less than $150,000 and will need moderate renovation work.

I own a duplex in Clermont, FL just outside of Orlando and initially wanted to split water meters between the two units, but the cost and amount of work were higher than expected.

Hey Cameron, for experienced investors I can lend up to 100% of the purchase and rehab costs on 1-4 unit properties.

He's changing the terms of the agreement, and you can choose to accept it or reject it.I don't think it's fair to pass this cost onto the tenant just because you are unwilling to stand up to the contractor.