@Jason Farmer
I think one of the problems is that there are no good resources about how to wholesale properly. This site has good resources for buy and hold in the free e-books. Flippers have a great resource in J. Scott's book, and his many responses here. But wholesalers have no such resources. And to be honest there are a lot of bad wholesalers out there. And like you, the good ones made lots of bad mistakes getting where they are, so that even they were really bad at some point.
To compound the problem, too many people use wholesaling as a springboard, with little or no knowledge, little or no money, no experience and unfortunately a lack of resources to learn from. And that is part of why the failure rate is so high.
It would be great to see some of the more experienced wholesalers put together a guide on essential knowledge for wholesalers. Or, in reality it would probably have to be several guides to do the job right. Maybe a starting point would be a good list of resources for wholesaling as a sticky so it can be found easily.
I will say that something most wholesalers could use as a valuable resource is J. Scott's book. Knowing how to estimate the costs of repair is a shortcoming of many of the new wholesalers, and that is a great resource.