Managing a Historical RP Economy
General Discussion
It's been ages since I last wrote something but had to take part in this conversation. As my RPG Sim project in OpenSim closed I moved back to first loving area in SL, Antiquity and we are doing major changes.
We used G&S system for a long time and tried to keep it alive in our RP but had the same issue as everyone else, too much production for not much demand. This is why Antiquity invested few years ago in having his own crafting system called [ACS] and was managed by Beatrix Muircastle who did an excellent job at hosting a market night every week and keeping the system alive for so long. The problem with [ACS] was the same as G&S... If you don't have to use it, why would you?
Tatiana said it, it's best to figure out the Economic system as you launch your RPG and even tough Antiquity is a long standing Sim, we keep the change to renew our RP system with a new HUD that manage your titles, provide class, levels, and a progression path and professions but mostly [ACS] have been rebuild from the ground so all is tied together. This means you have to wear the HUD to RP and the HUD require you to use [ACS] stuff in different ways so you have to consume product.
Picking the right systems and tools to help manage your economy : For me, to keep control over your economy you need to have control over the sources, the reason behind making our own HUD one of them. I used SpellFire that is like Unity before and loved it, but as it is possible for anyone to purchase COPY item so get unlimited food for a single L$ investment, this kind of ruined the project... Also we wanted to have a system that we own and was 100% free for our RPers and that was not available (or we didn't found it...). As we provide PAY system based on Level and Class, we provide Crafting System [ACS] and the HUD to tie it all together we expect to be able to keep a fair control over the economy and create a fair experience to everyone.
Strategies to help you get started : everything in the RP is purchasable only with HUD currency, pricing and products are created with scale, so lower level with less money can still get what they need to survive and as they progress they can get more and more, so it keep an incentive to play and progress. We reward people with Experience points for what they do and the "time" they spend in the RPG. If you can get everything from the start by using your L$... you loose the pride part of the game.
Closed vs. open systems : For us closed was mandatory as what we seek didn't existed the way we wanted it... This being said, a closed system could be spread in different sims it's just not gonna be available on MarketPlace, and will follow the same basic rules everywhere.
Encouraging healthy cash flow : We consider that giving experience point to progress when you either harvest, craft but also when you do social activities with other RPers encourage people to consume and so spend money. As mostly everything cost HUD money cash should flow around everyday.
Usability: [ACS] is really easy to use, it is based on rez and click for the crafting part, but to add realism to the RP, some crafting require you to be of a specific profession. Some craft require a minimal level, some recipe are availaible to everyone but other need to be purchased and learned. Once you understand how to use one part of it, you understand how to use it all as everything work the same. And... you won't be able to eat a full turkey with a single click... it will take time to eat it all 
How important is historical accuracy : For me it's very important as long as it doesn't create an unpleasant limit. For exemple you won't see BigMac in [ACS] (At least you shouldn't...), but paysant can eat other stuff then bread and broth.. (just saying)
For me crafting system is nice, but there is to be a reason to use it and there should also be means to do without them, this is why we are setting up store with NPC to allow people to purchase stuff at higher price then what local producer could offer, people will also be able to have stall at their home to sell product even if they are away and we hope all this create an immersive and fun RP.
We are still in setting up but the core is already working and all is focus on keeping people active, consuming and acting their role, like mentionned before, if you are a high noble, you are expected to spend lot of money so we'll provide you with expense to fill your paycheck 
