I have been quoted prices for P30 refurb units of 11K. I know someone that recently bought an A22 under 10K. A p21 is also a very good choice, around 8/9K. I think euros, I guess you do too?
Currently Teamworkphoto has offers for refurbed P backs. When you do not mind the crop factor a P30 (or P21) would be a very nice back.
http://www.teamworkphoto.com/index.php?mai...ath=515_546_548Prices are below the ones I got quoted a couple of months ago (mentioned in the first sentences above).
Having owned a Valeo. I strongly suggest swallowing a bit and going directly for the Aptus (also owned) unless you only work tethered or do not mind having a cable running from your arm to a HD/battery unit.
I am pretty sure at least someone from Leaf has contacted you by now as well
I have no experience whatsoever with a ZD. I have not even seen one other than on images on the Internet and magazines. I can say nothing about what would be for you the best decision to make or what way to go.
I also suggest just sending your question to the dealers of all 5 brands to come with their pricequote on the back that you might be interested in.