In first edition barter for a cost of living was 1 per in game month. The problem was for that this became irregular at best, a set of games could take place in a matter of days, or could take place over ten to twenty months. The first case, the players had a much greater opportunity to gain barter, and they were never charged for the month because the month didn't roll over. In the second case, the players would be hard pressed to get enough barter during play to sustain themselves for all that off-scene time. While in both circumstances it wasn't really disruptive, it was just a non-thing really.
• Irregular Expense
• Requires specific game pacing to have the desired effect
• Relatively unimportant
• Hoard based economy
In Second edition, the players are charged per session, as a regular occurrence. So they have a similar amount of time during each session to earn something to set aside for the next one. This creates economic color, where players have to try to earn their keep, rather then it being just by default.
• Regular Expense
• No matter the pacing of the game, this Game mechanic forces them to spend thought to Earning
• Provides useful economic color
• Expense based economy
The cost of a barter is arbitrary. The cost of a living is scaled on the former. So if you have 4 hours to play, and you need 3-barter to maintain your lifestyle, you must earn that much barter during those hours. This causes you to be concerned about barter as an expense, rather then as a hoard. Because these are GAMEY values, 1-barter today might not be the same as 1-barter tomorrow. They are representational of what a character needs.
So if you have 2 sessions take place during the same day, they still must pay the barter for each session, and the "living expenses" in this case has been zoomed in. They would represent many mirco exchanges rather then some big lump sum; 1 barter was stuff-for-half-a-day.
Characters in game don't count their "barter" they count their useful junk, tools, weapons, scrap, warm-stuffs, food-stuffs, etc. If you passed a week, then that was stuff-for-a-week, if you passed a day, then it was stuff-for-a-day. This is an Excellent game mechanic change, because it brings a cost to maintaining themselves to the gameplay and makes it relevant to the time You spend. Barter's worth is decided by Real Time, rather then Game Time.