It admittedly is a bit nerve-wracking, but the numbers on the project are good enough to support the investment and risk.

It is not good enough that they could succeed if they put in the effort (not to mention have some skill and some luck). 

If you are considering retiring here yourself, that may be good enough to purchase. 

Does the revenue good enough at least to cover the mortgage payment?

If it’s a good enough deal you may not require a full 100% reduction by the amount of the estimate.

Is $200 per month or $2,400 per year good enough?  

The only difference is that I care about the finished product and will not argue that it's "good enough" without charging thousands extra to make it right. 

Since I’m assuming it’s not a HUGE amount it wouldn’t be a syndication deal but rather a loan at a good enough percentage rate to interest someone if you can make it work. 7% paid each month amortized over 30 years with balloon payment in 3 years.

You have to learn what you are willing to accept as not perfect, but good enough. 

But, is it there fault that they were able to buy a property at a price good enough to make that kind of profit?