The problem with the cheaper ones is that they will break at some point. They are less expensive, so you can just buy another one. This sounds like a good plan.

A great plan, right up to the point that you are on day 2 of a 4 day trip and your bag breaks. Have you ever seen a pilot carrying their bag through the terminal because the handle has broken completely off? I haven't. But I have seen many passengers and flight attendants carrying their bags because their handles have broken off of cheaper bags.

If you are going to be a professional pilot, get a professional bag.