500eur is a bit much.
I’d be interested in buying one for less or pledging say… 250eur to get a mechanics only kit with no electronics, hot end, extruder or steppers.
(to convert an existing printer into a foldable one)
Hmm I didn’t thought of that, thanks for the suggestion 
(for the price, I may write something to explain my calculation then, the first time a friend kept saying I was too low ^^’)
(and thanks for sharing it !)
I think there is a great potential to bring P2P principle to material economics, in particular transparency of processes (who does what where) is essential - looking forward to http://3dprintskin.eu - are you going to run do it in english too?