And, therein lies the problem, for you today. At the moment, Shearwater 'owns the game' as far as DCs go. At one time, Suunto 'owned the game'. At one time, Dive Rite 'owned the game'. At one time, Liquivision 'owned the game'. It is a matter of supply and demand, and - right now - demand for Shearwater exceeds supply, at least in the 'used' market. You will probably not find much in the way of 'bargains' on used Shearwater computers right now. Next year, who knows?
Yes, I love my Perdix - I can read it / see it clearly UW. And, the company is reasonably stable. But, you will pay a certain premium for Shearwater right now, because they are in demand. That is not in ANY way a criticism of Shearwater, rather it is a compliment. And, many (of us) would say, 'The price is worth the value.' Of course, I can say it since my price is a bit lower than retail.