I am currently trying to evaluate a single family home and could use help from someone with experience to know if there is enough potential to move forward.

Jason Clifford the main thing is being able to evaluate a good deal from a bad one so that you can lend appropriately.I started private lending after I did a dozen or so rehabs.You may want to look at syndications, maybe even apt complex deals via syndications.Just my $0.02

Let me know if you have any questions about starting out and finding/evaluating deals

All the guys out there selling $3995 courses to teach the 'secret' of making a Billion dollars with Sub2 deals will not give you an honest evaluation of the strategy - nor will I.

Check out the #AskBP podcast episode #88: how to use the 50% rule when evaluating rental properties.

Especially when evaluating gross income and cash flow?

Every deal has to be evaluated according to the terms presented.

I would like to try to put together an option to purchase the property as is, of course after doing all the proper due diligence. ( I suspect that much of the electrical and plumbing is shot...lots of work to bring it up, but it could be a beautiful place) Can anyone point me to a basic investor formula to evaluate a reasonable offer for this type of property as is, and determine what the percentage and length of an option should be?  

I was just evaluating my bids for next weeks tax sale in Baltimore.

Well run, your NOI should be about 38.6kAssuming 4.125%/20 yr loan @ 1272 paymentsBack of the napkin numbers suggests a cash flow of 1945/moBUT TO YOUR EVALUATION with real expenses and financing