Yes, both Travis CI and Buildkite offer a Free Trial.
Travis CI is designed for Large Enterprises, Medium Business and Small Business.
Buildkite is designed for Large Enterprises, Medium Business and Small Business.
Pricing for Travis CI Starts at $69/Month whereas for Buildkite Starts at $2,999/User/Month.
Some top alternatives to Travis CI includes Codeship, Semaphore, GitLab, CircleCI, Bamboo, Buildkite, CloudBees Core, AppVeyor and GitlabRunner.
Some top alternatives to Buildkite includes Codeship, GitLab, CircleCI, Bamboo, AutoRABIT CI, CloudBees Core, Travis CI, AppVeyor and Drone.io.