Haven't played yet, super excited to. Might want to consult Vlambeer about the PWYW, as most companies wouldn't be happy about you making money off of heavily their work. Would be a shame to see something this cool taken down.
Viewing post in Wasteland Kings Together comments
I have had a response from Rami on forums, they seem to be fine with PWYW (with no minimum amount it's more of a Pay If You'd Like anyway) so long as the mod does not borrow materials from the main game while being standalone (thus allowing the user to potentially obtain some portion of the main game without paying).