2: Until you get at least a Nova-100 and decent gear, I would say it’s definitely worth it to collect and offload damaged goods at them. It can add up faster than you might expect. It generally stops being worth it sometime between Rigel Aurelius and St. Kat’s, though. Prices just get too steep at that point, unless you almost have enough for that shiny new set of armor or what have you.
Totally disagree. Even at the very start of the game it worth nothing. The only notable exception is damaged armor. Usually it's far more profitable to repair a damaged armor and sell it. Selling damaged armor does no good.
As for me it's useless to sell unpacked ammo, missiles, low-level fuel. Unpacked ammo is no good because it's extremely common and shops usually don't accept too much of it and even if they were to buy it all you wouldn't get enough money to repay your spent time. Missiles is not good for the same reason, though reversed. You usually don't have PILES of missiles in your cargo (after all they are kinda heavy and filling your space with this crap just for sale is a bad idea) nor you get a lot of high-level missiles worth to be sold. By the time you start to get some worthwhile missiles, you usually have some powerful cashcow and selling missiles seems to be stupid idea as they might come in handy when you fight with big ships or a horde of small ones. Fuel selling is just plain dumbness. Fuel is your second life resource (first being armor), selling it means killing yourself slowly. It's as if you are selling Elerium-115 when playing UFO: Enemy unknown without base milking bug abuse. In early game you are really dependent on fuel so you can't just sell it right away. It might seem attractive to sell those pesky helium rodes by 90 cr., but it's a huge risk. In middle game selling helium won't get you much money but at this time you may have a reactor that doesn't accept helium rodes and well, it's pointless to keep it in your cargo especially when you know it takes quite some space. In late game selling fuel is a bit better (considering you sell xenolithic one) but you can get far more money just by killing stuff and selling guns.
One of the most robust techniques to get tons of money, I mean TONS OF MONEY, is just getting two gems of teleportation to Elysium and teleporting in endgame systems and scavenging around without getting into a battle. It's insanely risky (it's usual to get followed by, say, Ares ships and get killed), but definitely the most profitable way. Though there is one hidden disadvantage which I always get hit on by: low-level shops usually DON'T have THAT MUCH MONEY to buy your high-level crap. I literally had a situation where I returned from my trip into the endgame world and could only sell some luxuries. Weapons, armor, none of that I managed to sell because not a single shop could afford it.
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