This has been an interesting thread- mostly by the "reasoning why" part.
Around 1986 I recorded my first 'studio' demo. I used a place called "Air Sound" in Boston- some Berklee guys might remember Bob Reordan.
Anyhoo... I was wanking one night- apparantly unaware of who was paying his own bill at the studio. I start going off on some diatribe about how the 'big bad record execs' they don't care about the little guys, etc. etc.- you know all the bullshit one can drug, eh hem, I mean drum up to validate their own "rockstarredness". He then explained, very clearly, how the business worked, and who paid for what. In short, if Notre Dame football doesn't generate revenue, their is no swim team or girls field hockey.
I learned alot more about music that night than how short lived radio play can be (actually, 3 different stations picked up the songs in local rotation- no small feat

- but my attitude was FR different ).
A couple of years later, when I worked at Daddy's Junky Music, those lessons from Sensi Bob came in very handy. I had a background in sales training along with being an actual player, a skill that many thought would come in handy. The ones who didn't obviously, felt that Daddy's should be in business so that there was a place to hook up with chicks from the previous night's gig.
There are guys at GC who are musicians, there are guys who are at GC who are salesman, and there are combos of both and neither. Each one justifies the stupid shit they can get away with (I believe that's called human nature) by knowing that they'll be enough people to try to get away with stuff.
At Daddy's, Monday was rental return day. 'EveryoneThatWantedAWarwickThumbForTheBigGig" would try to line up and return them. I was brought in to teach the guys that you could be a musician and still do proper 'qualifying the needs' and follow up procedures. You know- coming in early and calling the Neumann customer- Hey, how did your recording go last night?"
Duhhhh.... what recording?
The bottom line is that if you can show the guy how he can make the equivelant back to out weight he restocking fees- and NOT in front of other customers, you'll likely do OK- made up in discount on something else, etc. If he's still a wanker.... then we'll go to step two.