Lasso plans are per site. When you install Lasso on a WordPress site, you're adding another site to your plan which increases your monthly/yearly subscription.
But what if you want to add Lasso to a staging site?
Currently, if you add an install to Lasso, it'll start off deactivated in your account. If you want, you can then activate it by flipping the Active toggle to the right, turning it green. A popup will warn you that you're about to increase your bill.
You will only be charged, in a pro-rated fashion, for the time your install is activated.
For example, if you keep it for a month it's $19. But if you keep it for a day it's only ~$0.63.
We hope that's fair.