We've bought a few from Crew Outfitters, who seem to have the same prices as the Flight Attendant Shop. I've never heard of any of the online shops even asking about crew status to sell luggage. Travelpro won't sell their "professional" luggage direct, but unless you're trying to get an employee discount, no one else seems to care where you work.

I've got a FlightCrew3 that's on its second set of wheels and starting to show its age from getting checked while full of beer, but it's survived almost 15 years of getting kicked around so it'll definitely get replaced with the current model when it gives up. The only downside is that it's heavy and at DEL it's often impossible to avoid the check-in counter for international flights, leading to my bag getting weighed and me having to talk my way out of checking it.