I have a Phase One P25 H mount digital back for sale for $3700. It is tether-only, however, because it had an accident and the left two buttons do not press in properly. I bought it knowing that, and have used it very successfully. Does perfect captures. The end result is that the screen works, card works, battery works, but you cannot fully control all the settings and navigation on the back without these two left buttons working. However, tethered, everything works as it should. I believe you can set the settings tethered, and then shoot to card. That is why it is discounted about $1300 from typical selling price for these. Includes 2 used batteries, and charger. Great if you shoot tethered....and you would be silly not to (the P series is not very fast to work with on-screen, for checking focus, etc. If you shoot MF, focus is more crtitical, and you will have a much higher hit rate if checking on a laptop.
If you want the best bang for your buck for field use, I also have an H mount Aptus 54s (which now works seamlessly with Phase One software). One of the many cool things about the back, besides the huge touchscreen, FW800, huge battery capacity, and the fastest shoot rate of any 22 mp back ever made, is the ISO 25 setting (goes up to 400), which allows you to shoot wide open at f3.2 in direct sunlight at 1/800s. No ND needed. it is $5900. It also has the much sought after color palette of Leaf.
I can accept PP or bank transfer. I am very established online, in forums, eBay, so you know who are dealing with. I am in Toronto, Canada, but have bought and sold internationally many times.
When you message me, please send me your direct email. We can also Skype video chat and can show you both that way.