If something goes wrong with the database provided by the customer the service will go down. Or just be slow, which is bad enough. Requests you make to "Notion" still suck resources when they are waiting for the customer database.

So far as pricing I think many SaaS stumble through life, one day you take the plunge and make a 3-column pricing chart (it works for the phone company) or 4-column (from $199 a month it jumps to "starting at" $4999 for the 'Enterprise')

I would rather pay an 'everyday low price' (Southwest Airlines) than 'pick the plan that is right for me' from a list of options that doesn't make a lot of sense to me.

SaaSers go with the $C (constant) a month plan instead of the $V (variable based on what you use) plan because it is harder to get credit cards to let you bill $X (variable) recurrently.

The two schools on pricing are cost-based and value-based; they are both wrong. Profits come when cost is greater than value; you don't need value greater than price to make a sale but it sure helps. (e.g. markets may be irrational but it doesn't mean the marketer should be)