If an investor performs proper due diligence and buys right, the investor knows the total return though exit of the property at the time of acquisition.  

Using a service is probably better because it allows for consistency with is a huge key.

Make sure your contract states that keeping the earnest money is the other party's sole remedy and not specific performance.

Regarding historical performance every project we have done once stabilized has performed at or above our original projections used to sell them in the beginning.

I will also be a nice guy and get enough of a down payment out of him to cover the cost of the credit repair that I will perform for him so that he can cash me out early, once his repairs are complete.  

If you manage your own properties, perform repairs, etc this is sometimes the case.

Currently most interested in hard money lending and non-performing notes.  

Your IRA can lend it to other investors, it can partner with other investors, it can buy notes that are performing or non-performing.

Just keep in mind that looking at the real estate cycle is entirely focused on past performance.

Even if there might be a loophole, I'd sue for performance and attach a lis pendens to the title.