Yes, the dealer has a right to bluntly "not discount" if demand exceeds supply (this happens with cars all the time when a new model comes out --i.e. try to get a discount on a Honda S2000 or Plymoth Prowler.) But the real issue here is how the dealer handled the customer when he could not accomodate the customer's needs. A simple explanation such as: "Maggies are in very short supply at the time and therefore unlike many other of the lines we sell, I can't discount them." But I can .....
If the dealer leaves the customer with "a good taste in their mouth" (no matter what the pricing structure is at the time or whether any sale is made) both the customer and the dealer benefit. The dealer benefits when the customer returns to buy other stuff that may have been sitting around for a while, or some high margin stuff, such as cables. For example, my local dealers all know that I buy on eBay and audiogon, and two of the three except that and work hard to fill the gap with respect to convenience and stuff that is not available on the net. I may not have spent $10K with my local dealers, but I have bought a lot of high margin cables, SACD's, etc. and over the course of the year, have spent more than some of their mid-fi customers buying complete setups.
In the case of the Maggies, when the dealer handles this more professionally, as per the examaple, the customer benefits by knowing the dealer couldn't help him this time with respect to the current purchase, but the door is open for the future -- a true win-win situation. This Maggie dealer clearly blew it, as he has lost much more than a Maggie sale -- he has lost a customer forever. And customers, unlike Maggies, are always in short supply.
--Lorne