Well, CRC were doing non-camo pinned singletrack rims for £14 each (I got some and they’re very easy to build)
http://www.chainreactioncycles.com/Models.aspx?ModelID=20807
On One were doing the hubs for about £22.50 for the pair
http://www.on-one.co.uk/c/q/wheels-hubs-and-rims/mtb-hubs
And you can get 64 spokes From these guys for £16.64
http://www.sdeals.com/oscommerce/index.php/cPath/35_54
Meaning I could build a virtually identical wheelset for £67.14.
Personally, I can’t see them ever being a £239 wheelset (maybe at full retail, but you know, duh!! who’s gonna pay that for deore hubs??)
That leaves them with a bill for the build (1.5 – 2hrs absolute top), and postage. But remember, they’re not buying their bits retail, so the margin will be different (though not particularly high I would bet).