Going off site is a common way to get scammed, but not always. 

A more common and practical approach would be to calculate your return on equity. 

This is common when unrelated people share rentals, I suggest if you want the loan you get the information.

Investors love lower income areas.Its not because they want to fix and flip but rather to rent for positive cash flow.The turnover rates are high, so inventory is always there and 15% ROI or better is common.

Check FIRST if rentals for the area it is common to include utilities in the rent charged per month.If all landlords are doing it then you can waste money separating out as the tenants will move down the street.If landlords separate out utilities and is common for the area then move to the next step.

No one wants to brag they lost thousands but believe me it happens all too common.

That is a very common question and always falls back into what is your goals and current financial abilities.

What would be the common way to calculate cash flow?

Note-buying can be great and a great business, but here are the pitfalls:1.

If you stick with what's common on figuring a rehab then simply take your ARV x .65-.70 = {amount} then subtract your repairs, then subtract what you want to make on the deal.