Runestone Interactive offers WeBWorK hosting for a simple $100 per course.
For more details, please visit the information page at Runestone Interactive: https://runestoneinteractive.org/pages/webwork.html. (This page was just updated, so if you visited it recently, check that you are not seeing a cached version.)
This service started in Fall 2020 in response to the pandemic to support instructors who had a new need for an online homework system. This coming academic year, the MAA is discontinuing its hosting service, and Runestone is ready to provide hosting to those who find themselves in need. If you have any questions about migrating, or any other questions about this service, please either write to me or post your questions publicly here.