As a guy that used to buy from a tool truck, and now buys industrial tools at my current manufacturing job.
As a couple people have mentioned, if you can get to know the local tool truck driver and spend some cash with him, he'll cut you a pretty good deal when spending a few hundred bucks. He's floating so much cash and getting run out on by so many piss poor mechanics, if he sees cash (or even credit card but paying for everything up front), he'll likely jump at it. He's got 50% markup on most of his stuff, especially hand tools, so as they say, cash talks...and you know the rest.
Snap On Industrial usually used to be a pretty good deal, 4 years ago it was 25% off most anything and 40% off of "industrial" tools. (If you're not familiar with Snap On Industrial tools, they're sockets, ratchets etc. that have a black "industrial" finish on them, instead of being chrome dipped. I'm assuming they're cheaper since the cost of chrome plating is taken out. Of 3 different Snap On trucks I've been on, I've never seen any "industrial" finish tools, so I'm guessing they're exclusive to Industrial customers.) Sadly about a year ago I noticed our discount went down to 10% across the board. I asked my Snap On rep if we'd fallen below a spending threshold, since I only place a couple of orders a year, but he said they lowered the discount company wide.
Lastly, shortly after I started my current job, we needed an air hammer roll pin punch in the shop one day, I noticed the Snap On truck across the road and just ran over to see if he had it. He gladly sold it too me, and asked if we needed a tool truck to stop by on a regular basis. I told him that we generally ordered Industrial, just needed this short notice. He quickly informed me that he didn't honor Industrial pricing or Industrial returns. So all that to say, if you've got some returns that were purchased on an Industrial account, either do it through your rep, or don't mention it to the driver where they came from.