Whenever I see free or cheap courses, training, certificates, etc come up as deals, the comments always point out that they aren't worth doing and won't get you a job.
I generally agree with this. However, are there any free/cheap courses/completion certificates you've done that you think have been good value?
As an example, for me I think a free course on Writing in Plain English I did has been the most useful.
Any MS Excel course, especially the advanced features of excel. Can be extremely handy in multiple jobs.