If you wanted to view this strictly in terms of dollars and cents your first step would be to get an appraisal of the property. And by “appraisal”, I mean an appraisal that includes an exhaustive analysis of the supply/demand, listing vs. sales prices, lots of really similar comparables, etc.. This would not be a good assignment to shop around for based on the amount of the fee – you would want to find the old pro and pay their price.
Just guessing, but I wouldn’t be surprised if the $1mil turned out to be a lot less, which of course would cut into your returns.