Hi, thanks for asking. We do not have any “pay as you go” option. We plan our server hardware needs based on the number of subscriptions we have. So if we sell more keys in a month, we rent more dedicated servers.
sometimes the volume is 800k or 500k
My recommendation is to use 3 api keys. This gives you up to 900K conversions each month. Of course, you can buy more keys anytime and/or cancel subscriptions for keys you no longer need.