I've always treated the world's TL as what it can produce on an industrial scale and make widely available. Assuming there's robust interstellar trade going on, I'd say there are probably importers on Oriflamme who have some Tech-11 and -12 stuff available, but it's going to be much more expensive than the "list" place on Aubaine. You're effectively paying the item's price, plus interstellar shipping (probably 4 jumps), plus warehousing on Oriflamme, plus whatever the importer's cut is. So I'd say availability is GM's discretion, but there should be a substantial markup for anything available.
As for why everyone isn't becoming TL-12, in theory that might happen given enough time, but the way I play it the demand for high-tech equipment always, always outstrips the supply by a large multiple. Aubaine is only one world, and it's not all that populous, which means there's only so much gear they can put out. This is also going to come into play when mounting an RCES expedition- it's going to be what's available, although RCES is both based close to Aubaine and relatively well-funded, which means they probably have pretty good access to high-tech gear.
[The real answer is to try to increase the TL on other RC worlds, but who gets the bootstrap? Places like Nike Nimbus and Eos are closest, but their populations are small. The obvious move is to bootstrap the Flamers, as I'm sure they tell everyone on a regular basis, but while they have the biggest manufacturing base they also have the farthest to go to TL-12 of anyone but the Spirans. (Who, by the way, think this is all pointless. Meditating in the swamp they will be, yes.) Also, in the back of everyone's mind is the fact that eliminating the technological edge everyone else has over Oriflamme might leave them in a position to ignore or dominate the central government. It's not that we don't trust them! It's...okay, well. We don't trust them. But seriously, it's a planet with a gigantic industrial base, an established record of military adventurism, and a PTSD-induced chip on its shoulder the size of Meteor Crater. You sure you want teach them to make plasma guns?]
[The most terrifying words in the Reformation Coalition: "Hi, I'm from Aubaine and I'm here to help you!" and "Hi, I'm from Oriflamme and I'm here to save you."]
As for why everyone isn't becoming TL-12, in theory that might happen given enough time, but the way I play it the demand for high-tech equipment always, always outstrips the supply by a large multiple. Aubaine is only one world, and it's not all that populous, which means there's only so much gear they can put out. This is also going to come into play when mounting an RCES expedition- it's going to be what's available, although RCES is both based close to Aubaine and relatively well-funded, which means they probably have pretty good access to high-tech gear.
[The real answer is to try to increase the TL on other RC worlds, but who gets the bootstrap? Places like Nike Nimbus and Eos are closest, but their populations are small. The obvious move is to bootstrap the Flamers, as I'm sure they tell everyone on a regular basis, but while they have the biggest manufacturing base they also have the farthest to go to TL-12 of anyone but the Spirans. (Who, by the way, think this is all pointless. Meditating in the swamp they will be, yes.) Also, in the back of everyone's mind is the fact that eliminating the technological edge everyone else has over Oriflamme might leave them in a position to ignore or dominate the central government. It's not that we don't trust them! It's...okay, well. We don't trust them. But seriously, it's a planet with a gigantic industrial base, an established record of military adventurism, and a PTSD-induced chip on its shoulder the size of Meteor Crater. You sure you want teach them to make plasma guns?]
[The most terrifying words in the Reformation Coalition: "Hi, I'm from Aubaine and I'm here to help you!" and "Hi, I'm from Oriflamme and I'm here to save you."]