You're misunderstanding the dynamic. There are many SAAS companies that present a public-facing abstraction of a "sticker price", but the actual price that large customers pay has no consistent relationship with that price, because of exactly the factors you're dismissing. No enterprise procurement department will agree to pay a sticker price, and few enterprises will be satisfied with "sticker service".
Why aren't companies honest and upfront about this? Sometimes they are. Slack, for example (https://app.slack.com/plans/T02EPKPG3) is pretty straightforward: you can pay $7.25 if you're a normie company, $12.50 if you have more advanced needs, or you can request a quote if you're a giant enterprise who's going to be expensive to support. The risk is that a company which really ought to be in the "request a quote" tier ends up in a lower one and then has mismatched expectations. I've seen one case where a sticker-price-tier customer was absolutely outraged that nobody would set up a call with engineering for him.
Right, but the problem is when a company can't (or won't) quantify a no-frills normie price. I don't think anybody is complaining about the fact that huge needy clients will cost more and so will need to pay more; the problem is marketing material that says "we will treat everyone like a huge needy client".
I think that, most of the time people think they've seen such marketing material, the intended message was really "we're primarily interested in doing business with huge needy clients". For some kinds of software it's fundamentally hard to reliably make money from small users.
Why aren't companies honest and upfront about this? Sometimes they are. Slack, for example (https://app.slack.com/plans/T02EPKPG3) is pretty straightforward: you can pay $7.25 if you're a normie company, $12.50 if you have more advanced needs, or you can request a quote if you're a giant enterprise who's going to be expensive to support. The risk is that a company which really ought to be in the "request a quote" tier ends up in a lower one and then has mismatched expectations. I've seen one case where a sticker-price-tier customer was absolutely outraged that nobody would set up a call with engineering for him.