I calculate the returns on the entire investment, since your debt applies to the entire investment.

Are they going to start paying down that credit card debt, turn over a new leaf, and avoid bankruptcy for the next decade? 

Also do you have any debt?  

We have tried multiple local collection agencies, and we have not received a penny for over a hundred thousand dollars of bad debt submitted to them.We keep hearing, "It takes time" but it's been well over a year with the most recent one.

Deduct NEW property taxes after you buyDeduct home insurance costsDeduct maintenance percentage, typically 10%Deduct vacancy+tenant nonperformance percentage(we recommend 5% for Class A, 10% Class B, 20% Class C, good luck with Class D)Deduct whatever dollar/percentage of cashflow you wantNow, what you have left over is the amount for debt service.Enter it into a mortgage calculator, with current interest rate for an investment property, to determine your maximum mortgage amount.Divide the mortgage amount by either 75% or 80%, depending on the required down payment percentage - this is your tentative price to offer.If the property needs repairs, you'll want to deduct 110%-120% of the estimated repairs from this amount.Be sure to also research the ARV and make sure it's 10-20% higher than your tentative purchase price.As long as the ARV checks out, this is the purchase price to offer.It is probably significantly below the asking price.

For instance if this is a $10M portfolio that's levered with loans totaling $9.1M, there's no equity that can be pulled but if this is a $1M portfolio with $100K of debt, its a different story.

If you have a lot of equity and little cash flow, you should consider accessing that equity to use elsewhere.Another factor to consider is your interest rate on the debt.

To Sum it up, its a good idea if you can exceed the cost of capital (higher rate than your cost of debt) with what you earn on your heloc/debt you pull out and invest.The question is how much gains above is enough to substantiate the risk of your variable interest rate, well thats up to your personal investing criteria.

Refinance into a debt service loan.

So for example I'm very conservative and don't want any debt on them because I feel this hardens them in case of a severe recession.