Xcode Cloud is Apple's CI/CD service, built into Xcode and App Store Connect. An Apple Developer Program membership includes 25 compute hours a month. Beyond that you subscribe to a monthly tier: $49.99 for 100 hours, $99.99 for 250 hours, $399.99 for 1,000 hours or $3,999.99 for 10,000 hours. Parallel test runs add up quickly: Apple's own example counts five 12-minute tests as one compute hour. Each build runs in an ephemeral environment that is destroyed when the build completes.
MacRent gives you a dedicated Mac Mini M4 at a flat rate: $15/day, $89/week or $159/month (M6 from $17/day), with no meter on build time. Register it as a self-hosted runner for GitHub Actions, GitLab, Jenkins or Buildkite, keep Xcode, DerivedData and simulators warm between builds, and use the same Mac as a full-admin development machine when CI is quiet. You can rent one online in minutes.