They do work with a D9, its the same trasnmitter.
ive got a d9 and a second hand transmitter I bought from a bloke who had a vytec, work great, you can even buy batteries cheapish on ebay withouut a new o ring or pay a fortune for a Suunto battery kit..
£150 is an fair price, think I paid £130 they usually go for around £160-£180 on ebay.
Davie.