That has been the case at Municipal Auditorium in Shreveport, former home of the Louisiana Hayride, and I suppose it still is. You can't tote your gear in. I must say they were very professional and careful, and certainly didn't extort a tip! As far as I know they were paid by the venue, because they didn't charge me anything, and there was no agent involved.
Can't remember if I OFFERED a tip, but I usually do if someone helps load my gear. It would be $5.00 though, not 50!