I would suggest you work out your formulas for buying, repairing, maintaining, and selling a property and/or the cost of holding a property to equal no more than 65% of what you have to work with even if you can get the deal all on your own. 

All things being equal, however, letting money just sit there might give you peace of mind but it won't give you returns. 

Repairs+ purchase has to equal a refinance that returns your money, where the payment+monthly carry costs are less than the rent you get.

If I refinance and cash out as much as I can and then collect a decent Option Fee, I not only pay all the underlying moneys (loan, rehab and CC) but between the two strategies I also have some left over potentially equal or greater to my profit if I sell outright.

Does that equal your selling price of raw land?

If they wouldn't go 50/50 with a repair that was of equal benefit, I would seriously explore obtaining my own connection to the city sewer system and abandon the existing connection. 

We're not talking about an amount of money that cripples me but all other things being equal I'd be happy to not own that first house any longer.

Even if the rates were equal, I'd still go with the cross-collateral option if available.

Also, our parent's generations "Million" probably equals about 3 million for us in current dollars.

So since it's giving you a CoC ROI of 9.89%, it must be assuming an initial cash outlay of ( ($281.73 x 12) / 0.0989 ) = $34,183.62.Edit: I think I'm right, because if I take 20% of your purchase price and add closing costs and repair costs, it equals $34,200 ;-)