Well roly, if such a feature would get implemented, it should be balanced wisely, in order to not to underpower the relatively new independent traders. On the other hand it should be obvious for all, that you would gain more money if you join a faction. But it shouldn't be so drastically, that trading with an indy is senseless. Not to mention the smugglers.
And the oxygen thingy: it would be nice, if the needed cargo room could be like... divided by ten, so that the quantity would compensate the profit.