This week's Spacelords release is the excellent Adventurers set – the original three-figure set plus a Special which I believe has not been generally available before.
So far as I can find out, this was a special figure for sale at a convention in Germany in the 90s and not sold elsewhere (if you know differently, I'd be interested to hear from you).
Set of four: £6.00 GBP
These sets are not available from the website. Order by email to: firstname.lastname@example.org