The more I think about a "no money" scenario in a Star Trek MMORPG, the stranger I find the idea that a purportedly advanced civilization would revert to swapping stone knives for bearskins....
[transmission initiated by Station X-17 on trade channel 21]
Dockmaster Bob: "Ah, Captain, how good to see you! I have the five containers of blorbocite you requested. All that's required to complete our transaction is for you to transfer five thousand credits to the station account."
Captain Jack: "Umm... we're an advanced society -- we no longer use money?"
DB: "Hmm. Interesting. Advanced society, you say? Well, no matter. We're flexible here; we accept hard currency."
CJ: "We're back to that 'no money' thing, I'm afraid."
DB: "I'll take a certified check."
CJ: "We don't have checking accounts."
DB: "I'll take a bank draft."
CJ: "No banks, either."
DB: "How about a credit note from your government?"
CJ: "Which part of 'we don't use money' was not clear to you?"
DB: "Well, what do you have to offer me, then?"
CJ: "Twelve goats? Very fine goats, you'll love them."
CJ: "No? Well, do you like beads? Ooooh, look at the pretty beads...."
[transmission terminated by Station X-17]
(And a tip of the cap to the "bookshop sketch" from "At Last the 1948 Show" featuring John Cleese and Marty Feldman.)