Yes, both Buildkite and AppVeyor offer a Free Trial.
Buildkite is designed for Large Enterprises, Medium Business and Small Business.
AppVeyor is designed for Large Enterprises, Medium Business and Small Business.
Pricing for Buildkite Starts at $2,999/User/Month whereas for AppVeyor Starts at $29.
Some top alternatives to Buildkite includes Codeship, GitLab, CircleCI, Bamboo, AutoRABIT CI, CloudBees Core, Travis CI, AppVeyor and Drone.io.
Some top alternatives to AppVeyor includes Codeship, Semaphore, GitLab, CircleCI, Bamboo, Buildkite, Travis CI, Razorops and GitlabRunner.