If cost is a factor then you could use batch testing as your default mode of operation and not bother testing individual commits at all unless a batch fails. U

If cost is a factor then you could use batch testing as your default mode of operation and not bother testing individual commits at all unless a batch fails. Using batch testing as a default would both reduce costs and increase merge speed, assuming that your commits usually pass testing. The downside of using batching as a default is that it wouldn't test every commit in isolation. That means it wouldn't necessarily be safe to roll back to a particular commit if that commit was tested as part of a batch. E.g. if patches A, B and C were tested together, then it's not certain that patch A by itself would pass the tests.