CI pricing (gitlab, github actions, circleci etc.) is all extortionate. When they price by 'user seat' (gitlab) or 'credit' (circleci), comparing pricing is like trying to pick a cell phone plan.
AWS Code Build will always be an order of magnitude cheaper, it's just slightly harder to set up but it works very well. It's unclear how all these other services will ever compete with that.
For example, to run a CI server on Gitlab for a team of 8 that never spun down, it would cost $492 per month on their 'shared' runners. On AWS Code Build, you get a DEDICATED ec2 instance for $223 per month and only pay for what you use when it's running.