More specific to Star Citizen is that ships are a crucial part of the game, and deserve any extra care put into them. But do we really need to have a gun that costs $10,000 to model, especially seeing as this isn't the only gun in the game?
I understand what you're saying now but I still don't think there's an issue. While the visual fidelity of things has improved greatly over the years, the tools to make things have evolved significantly as well. Workflow refinement and automation, the wealth of resources and knowledge bases now available, and the evolution of tools has made the creation of very highly detailed models and materials relatively simple and quick (and from these highly-detailed assets they can reduce the resolution to whatever the game needs easily). I'd be surprised if that gun cost more than a few days of one or two people's time.
e: I see the note about 2-3 weeks for completion. While I'm sure that they were working on other things concurrently, that is quite a long time to spend on one asset.