The 5-gold bars are sold I think by AFE, to allow people who are forced to wear white shirts and appaulettes to extract the urine about it.
I once helped somebody ferry an Islander back to Bembridge from Bucharest - I was along as flight test engineer, the pilot was a chap well known in GA circles, but also Chief Test Pilot at Britten-Norman. Given that the aeroplane was just out of the works, draughty, full of sharp bits (no trim fitted yet) and not all that clean, I wore an old RAF flying suit. Perfectly serviceable (and at FL120 over transylvania, my Irvin was great as well). My colleague on the other hand wore a white shirt and gold bars - it was very very noticeable how much more assistance and help he got from the various airport officials as we stopped en-route across Europe.
So, they have their place.....
But not for PPL club flying.
G