Jimmy, R300 is fine IF:
It's in your shop, and I can walk out with it 5 minutes after I walk in,
I can buy the quantity I want,
you've got various models I can compare,
and I don't need to collect from the supplier.
That's what retailers do.They carry stock for quick delivery, break bulk, handle logistics and provide a place for the buyer to compare products or get advice. And most would charge a 30% mark-up, or R295. If you're only offering 1 out of 4 of those services, why should I still pay your full mark-up. I don't see why I should pay you when you're running an inefficient business. Most of the time the retailer offers no advice (or wrong advice), hasn't got stock, and generally provides no useful service at all.
Custom orders shouldn't be any different; your usual logistics chain is already in place. Emergency orders and personal delivery (why can't you use a courier?) add to the bill, but that's not what the OP was asking for. He wants a retailer with stock of the product, which you're obviously not. Don't get upset because you can't make a huge profit because someone else provided the customer with what he wanted, and you didn't.
As for Esquire, they provide us with what we want, at a fair price. I don't see why the retailer should make 30%, just for having an account with the supplier. If I'm doing the research, ordering the stock, arranging for delivery, and taking all the risk, I expect to pay what the retailer pays, not an extra 100% mark-up for services I don't want or didn't receive.