I've had two as well. The first I lent to a 'mate' at work who then moved away and forgot to return it...
The second I bought last year from FB Marketplace - seems to be quite dodgy as the screen has a tendency to go mental flickering about every now and then. Sometime it 'sorts itself out' though, not sure what's wrong tbh but it's a pain in the arse.
I love the Vectrex, have done since it was first out when we we far too poor for me to have one as well as my 'proper' computer (I had a Ti994a yay!).
Anyway, any advice on fixing the screen flickering would be gratefully received as I'd love to get it working again.