I always start my service for free, and tell them at some point I’m going to charge pricing, but the first 100 users don’t have to pay EVER.
After I get ~50 – ~300 users, I tell them I’m going to set pricing. I usually do this with a pop up or email. They then have a drop down with “how much would you be willing to pay monthly for this service”
Usually you get some range, say $5/month to $100/month. I usually pick one standard deviation above the average. So in this case, let’s call that $60/month.
Then, I usually will A/B test pricing by changing it month by month with “sales” so my current customers don’t get too angry.
I’ve done this three times on my products and several times for others. Thus far, it’s worked very well. You don’t always want to capture the most customers to make the most profit. This method has you start at the top of what people would be willing to pay and work down.
Plus, you start with a user base for free that share you with their friends. Seriously, this has been the best way to jump start the business.