I get the idea behind it, but the numbers have to make sense. You forgo revenue now for more revenue later, taking into account revenue now can be reinvested and SaaS companies typical grow really fast. If you undersell by 20%, you don't have that 20% right now to spend on more sales/engineers.
If the customer is really going be happy with 30K worth eventually, get them there now instead of 18 months later.
If the customer is really going be happy with 30K worth eventually, get them there now instead of 18 months later.