Also, no arguing that the technology, being sufficiently advanced, might be indestinguishable from magic. You know who you are.
While cobbling togeather a workable setting, I got interested in how one does a fictional economy set in a place where matter annihilation plants can provide nigh-limitless energy, and matter fabricators can provide an inexhaustable supply of whatever your greedy little heart desires. I can only think of one force powerful enough to control such advanced technological horns-o-plenty.
Make the fabbers require both extensive energy input, and a relatively advanced AI to run it, and you've put two controls on these economy ruining fabrication units. Make it require blueprints for whatever you wish to have crafted, and there's a third control.
The energy output requirement means little enough, as we have already determined that annie plants could meet any energy requirements, given an annie plant of sufficient size. Of course, these things make anti-matter, so any local government that wants to stay in power for any length of time (as opposed to, say, being blasted off their hemisphere by a breaching annie plant) will strictly regulate them. The liscenses would need to be expensive, and the background checks thorough, but since so many industries in such a society would require immense ammounts of power, obtaining a sufficiently powerful annie plant to run your fabber is merely a matter of time and money.
The AI could be easily made more difficult to obtain. Again it is a matter of liscenses. You have to buy liscenses to grow your AI (not to mention buy the hardware to grow it IN), and you have to have a good reason to have such a powerful AI in the first place. Fortunately, since I'm attempting to make this a space mercenary game, having an AI pilot your warship is a sufficiently good reason.
Now, an AI is grown out of something called an AI Gestalt. Think of this as the base set of rules thatan intelligence operates from. It is massively complex, and hellishly difficult to create, much less create well. Most people purchase Gestalts from the government, who in turn put certain limitations on what the AI can and can't do. Common limitations are "Can't rebel against your meat-bag masters" and "Can't create unfettered AIs who COULD rebel against your meat-bag masters". You could also imput things like "Don't let the fabbers make doomsday devices", but then my playtest would be awefully short, and where is the fun in that?
Finally, there are the blueprints. Unlike the other two controls, this one isn't a function of beaurocracy. It's a function of skill. If the players can afford the fabber, and can get the permits for the AI and Annie Plant, then they can build whatever weird devices they can find the blueprints for on the Galactic Wide Web, or that they can design themselves. Since most people don't have both the scientific acumen and the financial backing to get design time at a decent sized fabber, and those that do are closely watched by governments who ENJOY being at the top of the food chain, the galactic economy is safe!
Next up: Why stealing money in the far future will still require high explosives!