Put yourself in the position of the 'middleman' the sales agent or dealer; would you work for nothing?
I agree 50% sounds like a lot but I notice you say 'up to'; what is the 50% on, the full machine that may be worth a large sum of money, or is this what is applied to lower cost items and options? Fifty percent of 800 pounds is a lot less than 50% of 80,000 pounds and often dealer mark-ups are scaled to compensate. I have no idea if machine tool companies do this but I do know that in some cases the discount that the manufacturer gives the dealer is only 15% on the machine price.
Also how is the 50% calculated? I mention above that the discount is 15% which means that the return to the dealer is 21% on what the manufacturer charges them. Fifty percent as a discount is high but 50% as a return on a sale is not extreme; this requires a discount of 33.3% which is fairly typical for what manufactrers offer their dealers on lower cost items.
Regarding buying ex-factory I think you will find a lot of manufacturers will never go for this. The very reason they offer discounts to their dealers is so the dealers take all the hassle of dealing with customers. Also do you really think you would be better off with independent maintenance technicians who will probably have little clout with the factory and never hold the hope that they can make 50% in the future selling you a new machine if they treat you well.