Whilst we're on the subject, I've got a couple of old manual guns that are going in the bin unless anyone wants them. One is quite big, the other fairly small but has a handy pc cord built in. Can post a pic if anyone's keen.
On the other hand they both have big test buttons so are ideal for getting your mate to fire down a cave.
The trigger market moves pretty darn fast (or has done over the last few years) and there is now a lot of reliable functionality to be had for (relatively) very little. People have been put off by the old (lower frequency) ebay type models which were a bit shit it seems.