It does seem like a good way to acquire more properties but how do they pay out as far as cashflow when you get say, 20 or so.

So it's unreasonable to ask for a general price because any number that someone gives you site unseen is either: so low that the builder will eat the cost, lucky and spot on, so high the builder covers the worst case scenario but the investor would over pay if there are savings because certain things I mentioned above are applicable. 

Always be willing to walk away, or, if you really want it you're going to likely pay above what makes the most financial sense to you based on pure math. 

1- Go the eviction route, Send them a 7 day notice to cure and if they dont comply get someone to cut the grass and send them the bill If they dont pay then go the eviction route.

But with the financed deal the renter pays the mortgage down allowing you to tap a percentage of the equity as a tax free loan.

Obviously you want to pay attention to your interest rates, cost of appraisals, and fees for refinancing.

The problem is the longer we go paying this payment the farther behind we get on everything else and the lender isn't reporting the payments to the credit bureaus.

She will be paying rent anyways with me so her paying me rent and building our future wealth when we do get married is a much bigger win than us both paying down someone else's mortgage. 

He said that we can just move the meter from our common area electric (which I pay) over to the socket for her electric in the meantime when he upgrades the base, this way she gets power and we will just go without lights in the basement and common area.

If you don't own the house yet, you really need to pay the guy otherwise it's a waste of his time.Sometimes roofers and pools companies will give an estimate based on google maps.