No - they are selling at manufacturer prices, but won't sell at less to retailers. No appreciation of business process and thus cutting the number of possible outlets to one...
I'm sure as a customer that you will be more than happy with that, but if we applied the same principle to everything a retailer sells, then that retailer can't operate any longer as they will not be earning a living. Raising it to a bigger level - if my Nissan agent decided to do the same thing, I'd be gone and you would be left dealing with Nissan Parts Departments who know very little about the Z range and wouldn't really care if they had you as a customer or not.
On the subject of panels BTW, the pattern panels for sills and wheel arches have diminished (if not disappeared). However, I have sourced some equivalent items in America which look to be better quality for not much more money. Supply may be a bit sporadic, but that problem is overcome, at least for the moment.