well, if it offers the 'play-ability' you're after then it's ok
you'd likely spend about the same amount on a guitar or bass if you demand something more than basic
imho it's also ok from the technology point of view
go to a shop and get a mini pc, a multitouch controller, a customized rugged yet small enclosure, hopefully good-looking, too...
mount everything, setup an OS to flash boot
write a graphic app that outputs controller data from objects, make it networkable
etc
probably even the basic parts will be in the 1.5 k Euro range
stock clearings from eBay do not count in this context...
cheers, Tom