LIFE ON TITAN
Trade Central is in the Downtown Crater just to the west of center. It can be easily targeted from your Local Services Menu when you're in the Downtown Crater.
Like all trading posts, they buy everything, but don't always give the best price. Trade Central is usually very busy so don't count on quick docking if a pirate is after you. Consider a quick run to the Alpha Trading Post instead. Best feature: most complete Sales and Needs List.
Alpha Trading Post
The Alpha Trading Post is located in the Alpha Crater near the entrance to the Downtown Tunnel. The hangar doors face the tunnel making Alpha Trading Post one of the best places to go when a pirate's after you. You just need to whip through the Alpha/Downtown tunnel, make a sharp right, and there she is.
Another advantage is that The Alpha Trading Post isn't generally as busy as Trade Central, so it's a lot easier to get into without having to wait. It still doesn't pay much for goods, but there's a good Laser Turret deal ($11,000) to be found there early in the offline game.
Highrise Trading Post
Highrise Trading Post is in the Highrise Crater near Light Well #4. Just enter Highrise and target it from your Local Services Menu. It's a pretty standard Trading Post, but entering it can be a problem if you don't approach it properly. It takes some practice.
Mines Trading Post
The Mines Trading Post is in the Mines Crater near the Light Well and Fred's Construction. Locate it by entering the Mines Crater and targeting it with your Local Services Menu.
It's a pretty standard Trading Post with one important difference. It never, and I mean never, seems to run out of Ore. This becomes important if you're trading with Downtown Moths for an exotic Moth as they require Ore for production.
Gamma Trading Post
Gamma Trading Post is located in the Gamma Crater in a ravine near Klamp-G DeFac and FeMill. It can be targeted from the Local Services Menu whenever you're in Gamma or parts of Riverside.
Gamma Trading Post is the worst place to sell goods. Their prices are well below what you would get elsewhere, even at another Trading Post. Keep alternatives in mind like Dr. Jobes, Klamp-G Weapons, and Riverside Components. I only use Gamma Trading Post when a pirate has gotten the best of me and I need to sell quick. Even then, I sometimes use the "Dump and Blast" technique before selling goods to Gamma Trading Post.
Resevoir Trading Post
Resevoir Trading Post is located in the Resevoir Crater and easily targeted from the Local Services Menu. If you're carrying weapons, you might get a better price at Resevoir Central, the place you start out at if you choose "Aggressor" as your initial occupation. Pricing here is typical.