GitHub has still been managing the orchestration and monitoring of runs that you run on your own (or other cloud) hardware. They have just decided that they are no longer going to do this for free.
So the question becomes: is $0.002/minute a good price for this. I have never run GitHub Actions, so I am going to assume that experience on other, similar, systems applies.
So if your job takes an hour to build and run though all tests (a bit on the long side, but I have some tests that run for days), then you are going to pay GitHub $.12 for that run. You are probably going to pay significantly more for the compute for running that (especially if you are running on multiple testers simultaneously). So this does not seem to be too bad.
This is probably going to push a lot of people to invest more in parallelizing their workloads, and/or putting them on faster machines in order to reduce the number of minutes they are billed for.
I should note that if you are doing something similar in AWS using SMS (Systems Management Service), that I found that if you are running small jobs on lots of system that the AWS charges can add up very quickly. I had to abandon a monitoring system idea I had for our fleet (~800 systems) because the per-hit cost of just a monitoring ping was $1.84 (I needed a small mount of data from an on-worker process). Running that every 10 minutes was going to be more than $250/day. Writing/running my own monitoring system was much cheaper.