"Artist representatives" is a suspiciously vague term.
Ultimately if one ticketing company offers a band 200k to perform a night and another company offers 150k then every band is going to go with the 200k - even if there is a dynamic pricing model for the fans.
Its my understanding that some NFL actually has an official deal to sell through Ticketmaster first - though presumably any of these other companies could have that deal if they paid the NFL more.
FWIW I do think ticket convenience fees should be eliminated (or made so they have to be listed upfront) and this would be good for transparency - but I am also pretty sure that doing so would ultimately just raise listed prices.