It was not an argument, but a statement.

If one model (pay as you go) causes harm to the whole industry (people know believe hearing aids do not work) then why would the industry continue?

I'm suggesting the model to use should be decided individually by members of the industry, not imposed on the industry as a whole. If some orgs want to use pay-as-you-go that's fine. If others want to offer more comprehensive service, that's fine too. I'm arguing for allowing the interactions to take place, even if some choices made are suboptimal.

They can.

As far as I know (at least for Canada, circa 2015) there were no laws or regs stating how, what or when to charge for services. --other than some kind of return period.

Because it's easier to get someone to pay $100 for something they aren't sure will work (and then have their beliefs confirmed) than to get someone to pay $1000 for something they aren't sure will work (and then have their beliefs refuted)?

Would you rather pay $100 for something you are not sure will work...or would you rather ay $0.00 to try it first?

And then still be able to return it at least within the first 30 days of paying for it?

I think it depends on the someone in question