This document explains Cloud Scheduler pricing details. You can also use the Google Cloud Platform Pricing Calculator to estimate the cost of using Cloud Scheduler.
Each Google account gets 3 jobs per month free. Note that the free tier is measured at the account level not the project level. For example, if your account has 5 projects with 2 jobs each, you will have 3 free jobs and 7 paid jobs.
|Job cost||Free tier|
|$0.10 per job per month||3 free jobs per month, per account|