Ok I'll be the wet blanket. Without analising the costs or the product in depth I will make this point. A low volume high R&D cost item will be expensive. Consider the following:
The Kaymar bar is also a tow bar and as such has to be tested to meet legal requirements. Then there is the cost of design and development. Add to that the cost of tooling (weld jigs etc). All of these need to be recovered. There is another aspect which is expensive and that is setup costs. By this I mean the cost to setup for a production batch. Assume it takes about 60 minutes to gather all the information materials and jigs for a specific operation like welding the main beam. The action of welding might take 5 minutes. If the batch size is 10 then you will have to load up the 5 minute with another 6 making it twice as expensive. If you only believe you can sell 100 then the cost of development is divided by 100 and added to the cost. If you increase to batch sizes and hopefully sell more units than the 100, say 1000 then the costs will go down appreciably.
The Disco in real marketing terms is not a high volume product. The requirements for a rear bar are much less than for a bull bar for example. I would recon that if anyone makes a bar they need to consider all the aspects of cost before they go into it, and I would expect that is what Kaymar have done and the price demanded is the result. If anyone (4X4Design) is thinking of developing such a unit be very aware of the manurfacturing methods and material costs. Also do not try and make it a multi purpose unit as Kaymar have done, just make it a simple replacement bar with better departure angles and you will have a small market, but a profitable one.