Jeeze... I guess I have to chime in on this thread now... considering that I own 10 of them!... but ... I also gig with them as they are the hardware that was cataloged with the Rogers kits that I own/play with both kits being Buddy Rich models. So...
In reality, the stands you are referring to are the Rogers #4403 which was actually cataloged as the "Rogers PRO Floor Cymbal Stand". It was later on called the "Swan-Leg" and has come to be known by that name ever since. I understand what "Chopsontops" is saying in his post, but in reality, the reason these go for so much money is that Rogers cataloged/supplied this model stand with ALL their high end kits from approx. 1962 to 1970, being superceded by a different design in/around '73 or so. So...
All the guys that play and/or collect Rogers kits from this period, and arguably the most sought after/desired era for Rogers, are after these stands to complete their kits. The fact that the #325 Swivo Extension Cymbal Arm adds height/angle to the stand is NICE!... but not the reason for the demand, as it were. In addition: The Rogers "Swan-Leg" cymbal stands function in a dual way as they can be used WITHOUT the Swivo tilter for those that prefer their cymbals FLAT with no angle, ala Buddy, to name but one.
I do in fact gig on Rogers drums/hardware and have to say that it is a great design. Super sturdy, and very light... which is an added plus when they are in one's trap bag and being hauled around. "Ploughman" is right in there on the "cost" : I haven't seen many, if any, go for LESS than $150.00 each... and truthfully, usually more! I could probably fund my daughter's first semester of college if I sold all 10 of mine! :-)
Tommyp