If they kill me and they paid for their ship with real money or in-game money, does it matter in the end?
To me, yes it does. In-game money that is earned by playing the game well is a part of the game. Paying real money to get a head-start prioritises those who can afford it, which I don't really like as an idea. But then again, I'm not really into MMOs anyway - I'm more interested in the Squadron 42 single player game.
What I mean is that if you get killed you still wouldn't know if the person that killed you had a ship they paid for with real money or not, the only thing matter is that he was a better pilot than you or you just had a bad time besides it's not like there's one ship that's above all other ships anyway, every ship has it's pros and cons depending on it's role. Honestly, I don't worry about it that much.
I think it's also important to know that buying more and more ships is not some form of end game, if mining is your profession that's the only kind of ship you need now going of and mine by yourself without protection is stupid so hiring mercenaries to protect you is necessary to protect your cargo.
Side note but I find this about how diffrent professions goes hand in hand kind of poetic:
"A trader will be running a long haul for cash, it will take a long time to load and unload the ship and then a long time to travel."
"A mercenary will accept payment from a trader in order to protect them."
"A pirate will be attacking these trade runs in order to make some quick cash, steal a ship, steal some of the cargo, for fun."
"A bounty hunter will be hunting down known pirates for their crimes, then get paid to do it."