They're early adopters. Guessing they're worth a lot since you're counting on them.
Normally early adopters are the cheapest. The "shut up and take my money" type that make up the initial marketing channel. So it can be a bad sign to start out with a high customer acquisition cost.
I guess, if you're calling development and startup cost zero.
In this case they're paying more for the feedback/interview than for an additional user
Depends on the industry. In my world (B2B SaaS) we are spending $90 - $300 for every new lead generated. Of course, every new lead doesn't become a customer. We have to spend $3000+ for every account added to our free tier!
That's really expensive! That means you are spending $3,000,000 for 1000 free tier users. May I ask how much does your Saas charge paying customers? I would love to know the potential revenue to justify the expense.
They said it was B2B SaaS. It's easy for the lifetime value of an account to be 100k+ and to have pretty good conversion from free accounts.