The thing that brings it back to mind was an IM's recent post on the 4NCL site
Minimum conditions (to cover costs):
Hotel accommodation + meals during the team's competition.
Return expenses of 'low cost flight tickets' (e.g. easyjet, wizzair, ryanair) from a European country.
Pick up and return to airport and to hotel accommodation and later to the tournament hall (if required).
Lift to airport for return journey home once the weekend's games are over.
£100 per each game.
Now I don't know whether that is cheap, expensive or just right. And I do not know because there is no set rate - the one thing unions do define, generally, is the cost of their members labour. I also recall at the ECF when we were looking for coaching capacity the charges ranged from £10-£60 per hour. We did not know if one was cheap or if one was expensive, as again there is no set rate.
I would also suggest that a lot of clubs are put off inviting masters to give simuls because they have no idea of what the cost will be.
In the trade in which I trained, journalism, the rates of pay were set for virtually everything, including wordage for freelancers. I'm just wondering if those who make a living from chess - in whatever form - got together and formed a union whether they would not immeasurably improve their own conditions.