If you have examined the matter and have determined you are still in the right, you can turn it over to a collection agency and let them pursue it.

I'd also examine if there is any investor activity (large or small in new developments in any neighborhoods adjacent to where you are considering purchasing. 

I was a mix of confidence and nerves. 

If you materially participated in the rental this could be another strategy to examine.

Unless that doctor has a modified AGI of less than $150k (which is unlikely for a doctor, trust me) or has a spouse that's a real estate professional, there's no way he can use regular real estate losses to reduce his taxes...If his return is selected for examination he'll be hit with back taxes, interest, and penalties.

Other costs - need to examine item by item, and many will be subject to your accountant's interpretation.

And generally, no sophisticated investor would make a go/no go decision based just on the return (and without knowing enough to closely examine the risk as well).

It definitely seems like you've built a solid foundation.Transitioning from the learning phase to taking that first step can be a bit nerve-wracking, but as you mentioned, sometimes the best way to learn is by doing.Have you ever thought about attending conferences or larger networking events?

This is why you have an engineer and foundation specialist examine, solution and cost.  

The first one is always the most nerve-wracking!