Handling Money
There is no cash of any kind in use in the Zone. Every so often freelancers will dig up a cache of British currency stashed away somewhere, but it cannot be spent in the Zone, so it is usually sold to one of the bars for a fraction of its value. Recently, government agents have been paying people in gold bullion, but that too has little value in the Zone and is usually sold very cheaply to a bar.
Your Account
Every freelancer has an account with the Gatehouse. Missions and contracts are paid in KeswickBucks (shortened to bucks or b) directly into the accounts of each freelancer. Side missions from NPCs will usually pay out in bucks directly deposited, but sometimes they pay in goods or favours.
If you wish to sell something to another player, whether it is goods or services, you need to let the staff know. The referee team will be tracking everyone's accounts and keeping banking records. If you don't declare a transfer to the refs it didn't happen, with all the possible consequences that implies.
Selling Stuff
All loot items can be sold to the staff. Food and parts will always sell for less than their listed value so if such things are useful to your character it is recommended you keep them and use them to offset against living costs. You can also sell items to other players assuming you notify the referees of the exchange.
Barter
A lot of NPCs will avoid holding too much wealth in accounts at the bar. Information brokers who move from place to place need to be able to take their wealth with them as they travel, so they tend to barter in goods rather than currency. Most of those who have taken up permanent residence in the Zone for one reason or another also operate largely by a barter system to take themselves out from under the shadow of the smuggling gangs and the bars. Whenever such people need credits or bucks to pay freelancers they simply sell goods to the relevant bar to get the credits required.
There is no formalised set of values for anything, so all barter exchanges are carried out based on the relative needs of the two parties. Most experienced Zone residents know that the best prices go to those that seem to be in least need.
Moving Accounts
The different bars all operate different currencies that have no exchange mechanism. When someone decides to quit one bar and move to another they have to buys goods at one bar that they sell at the next. The sale price will never match the buy price, so moving to a new bar is usually a minimum of a 20% hit to someone's wealth.
The Wider Economy
The economy of the Zone is something of a messy affair. Unlike most external economies, very little is produced in the Zone, save for information. Thus the economy grows as new things are learned about the Zone, new materials found and new scientific breakthroughs are made. As information flows out of the Zone, it pays for goods to be brought in and the cycle goes on. Knowledge is the true wealth.