I remember the UA bombing thing, where someone would collect a bunch of the thargoid parts and sell it at a station so it would start taking damage and then go into lockdown (or something). I'm not familiar with hydrogen bombing. What is that?
Profit margins determine BGS economic effects, not demand/ raw purchase price, which is dumb, and hydrogen bombing is (was?) an exploit where you washed goods through an FC to create the desired effect.
So, let's say Station A buys gold for 9000 credits. If i buy gold for 8000 credits and sell it to Station (i.e i make a profit), Station A's owner gets +ve influence and economic effects.
If buy gold for 10,000cr and sell it to Station A (i.e i lose 1,000 cr), Station A's owner suffers negative influence/ economic effects.
From station A's perspective, both transactions are identical, but one is good for the station, one bad.
You can use an FC to set an artificial purchase price. So let's say you go to a station and buy hydrogen fuel (the namesake commodity, but could be any commodity) for 100cr, and you could normally sell it at station A for 120cr (profit).
If you load it onto your FC and sell it back to yourself for, say, 2000cr, all the credits go back into your pocket, so you don't really lose anything, but if you then sell that Hydrogen fuel to station A, it thinks you bought it for 2000cr, and so records a (fake) loss of 1900cr/t, causing severe negative effects for its owner.
I'm unsure if it still works, but it was a substantial exploit at the time FCs launched.