You should be charging a % of revenue as people scale. That way you align with taking value as more value is driven. If you look at companies like Shopify over half of their revenue comes from processing fees. Maybe price is a good place to start to get people in but probably not best model long run.
There's a lot of justification for ethical percentage-based businesses. Particularly if the service provided is provided on each transaction.
It also means they don't make any money if their customers don't make any money. It's a good incentive for providing a quality product, over say, a single lump sum purchase price.
Variabilising all a company’s costs is every CFO’s dream: it makes all projections perfectly linear and totally eliminates any risk as zero revenue doesn’t create a loss because all costs also go to zero.
At least, in the start-up phase of operations.
Later, when economies of scale kick in and break-even has been far overcome, one seeks to negotiate smaller unit charges, primarily to capture more of the added value for oneself, and partially to reduce visibility of one’s revenue.
That's all definitely true. I think the cloud is a terrible value proposition for anything that's not a startup, for instance: You will safe a crud-ton of money paying your own IT staff instead of paying Amazon's IT staff, provided you have a stable business with relatively predictable needs.
Arguably, once you are a big player in a space, you should ideally have the clout to negotiate a better deal too.
Ethical companies don't exist. The only point of a company is to make money. If the company lets ethics get in the way of that it will be replaced by a more effective company.