I don't know about Nathen Arnold, but Nick Morello's prices are a complete rip off. I got banned from his group the other day because he was posting "flash deals" or "hot deals" or something and someone started asking questions. I posted a link to Amazon that answered his question, but just happened to be over $20 cheaper on the exact same item. This was a sub $100 item, so it's not like they were $20 cheaper on $500 tool.
I noticed this with anything he posted. You could almost always find it on Amazon for 20-40% cheaper. Not sure why anyone would buy from this guy for these prices, not to mention after seeing his reaction to me answering the guys question with a link to Amazon, I strongly suspect if you ever have an issue that you would get much better service from Amazon.
The other issue as far a tool truck is that it's my understanding that these guys don't offer financing, only layaway. My friends that are mechanics rely on credit from the tool trucks to buy tools and say that is often the only reason they are willing to pay more for re-branded items than they would online. So if the prices are higher, but you still don't offer the benefit of credit, you really have no advantage that I can see.