after another extended research about the ondes martenot (which proofed to be quite difficult..) here is what i found:
the ondes martenot was discontinued when maurice martenot's assistant retired in the late '80s.
since then no real ondes martenot was built (martenot's son wanted to build a digital one once, but apparently never did). that's why they are so rare and even someone with a lot of money (johnny greenwood) could not get hold of one. (actually he has one, but wanted to get a second, because he was concerned about the poor thing being hurt on tour)
the next best alternative is "L' Ondea". It is a replica, built by the french company SEAM.
(S.E.A.M. 9-11 bis rue Jean Jaurs , 95130 le Plessis-Bouchard, France, FAX: 01 34 15 66 14)
unfortunately it is monster-expensive: one is 15000Û. (about $20000) and, as mentioned before, it is really hard to get in touch with them. someone ordered and even payed for one and did not hear a word for years...
the above mentioned "french connection" is a controller by the british company analogue systems (http://www.analoguesystems.co.uk) which has no tone generation built in. is has several control voltage outputs that have to be connected to some kind of analog synth to make it sound. it was built for johnny greenwood, after his fruitless attempts to get a second ondes. the sound of it relies totally on the synth you use with it, which might be very different from the unique ondes martenot sound, which is produced using the various different speakers/resonators. but it is nontheless a really cool thing. (£1050/$1400)
i hope this helps, even if it does not at all help us to get an ondes martenot ... )-:
robert