For private/small open source projects I would highly welcome such a pricing tier from travis-ci but 69USD is just not in my pocket (not saying its unjustified though!).
For larger open-source projects that rely on many builds throughout the day/month, this might be a bigger problem.
So while its "free" marketing, it might be much more crucial to our open-source structure than we think it is (which might be a problem as well).
And I think we can all agree: open source software is an important part not only for the industry but our lives :)
Containers are a solution for this right? If I was open source I’d run CI in docker or similar so you can easily run it locally or on a server.
The assumption is people doing FOSS can’t afford maybe $20 a year to spend on some kind of elastic compute to run this or don’t have a computer powerful enough to run it. I doubt this is the case and if it is just do without CI - just run your tests from IDE before pushing to master.