Keep in mind not everyone needs to buy a big ship to Captain. The shortest path to leadership is serving. TEST has a LOT of big ships that all need gunners, engineers, etc. and my guess is, those who serve well and often will get a shot at leadership eventually.
And yeah, $5k is steep. If it’s true TEST has over 70 Idris, I can imagine small groups of Idris owners selling them to jointly buy a Battle Cruiser. I still think though, the ultimate weapon of the void is the Eclipse. Be heard, not seen.