If you’re already using Xero, Xero Projects is an add-on that costs $7 for one user per month, plus $5 per additional active user per month.
If you don’t use Xero yet, you’ll have to subscribe to one of the three plans first to be able to buy and use the Xero Projects add-on; the Starter Plan costs $25 per month, the Standard Plan is priced at $40 monthly, and the Premium Plan is at $54 every month.