Wholesalers pitching inflated numbers is inevitable, really. Think about it. Who wholesales as their primary strategy? Newbies who have no cash, credit, or experience; and people working for wholesale companies that prey on newbies with little to no experience but with some cash and/or decent credit. They're just following that company's training. Please understand that is a general blanket statement which applies to the majority. I have ran across people new to the industry who began wholesaling and actually gave accurate, legit, well researched numbers, and I am sure there are those individuals at wholesale firms who strive to do the same. David may very well be one of them. Those type people have proven to be the exception though, not the rule. Which sheds a bad light on all those who wholesale.
Wholesaling should not be your main strategy, but rather incorporated into a suite of strategies for you to use where appropriate. You can bet a wholesale deal coming from an investor who owns properties and has multiple other properties under contract with the intent to purchase them will look a lot different, and generally be more accurate, than a one coming from someone working at a wholesale firm or trying to get started in real estate investing.
...Just my two cents.