When acquiring a rent roll, whether it's just the asset, the office & business with the rent roll or even shares in the company that holds the rent roll, there are many considerations before you make the call to the bank.
1. Equity - do you have enough equity in your existing rent roll to fund 100% of the purchase? If not what other equity do you have? Too many times I see prospective buyers putting no thought into how they are going to fund the purchase.