Screen Used props has a Cardassian Desktop Computer on its site for $ 3,999. It is a nice piece, though saw little screen use. It was first used as a Trill computer before being retasked for Sloan's office, where it is seen on his desk.
The world famous Jörg, Star Trek's greatest living prop identifier had this to say about it:
"As far as I know, the prop first apppeared as a Trill desktop monitor in "Rejoined". It was then modified and later was seen in Sloan's mind in "Extreme measures" just the way it looks today. You can see that it still has the same grey/blue colour on the underside that it had as a Trill monitor in "Rejoined". It might have been reused between Seasons 4 and 7 which would explain the colour change and modification (there's no Cardassian symbol or written language on the monitor, so it is not necessarily Cardassian), I can't imagine them changing the colour just for the brief scene in Sloan's mind. I'll let you know when I find out more, for the moment I can just say it was once Trill and then was seen in Sloan's mind. Everything I know, I posted at EAS:
http://www.ex-astris-scientia.org/inconsistencies/reused_props1a.htm "
Now, I think it is a beautiful piece, but way overpriced. This is a $ 2,000 - $ 2,500 piece. Why? Well, I have bought three Star Trek monitors, Picard's from First Contact, Picard's from Insurrection and Martok's Klingon computer. I paid $ 2,000 - $ 3,000 each and they were all much more important pieces and used more than this one. So this seller (much of what is on Screen Used is on consignment), needs to come to grip with reality.Also, I would like to see some provenance on this piece. While I have no doubt it is real, we have no idea how this got out. Another Star Trek back door piece one must assume. It sold at the Profiles in History sale and as I have said before, that is not provenance. You can see that item page on the Star Trek Archive here.
Alec