Could just as well be at no additional cost. If your monolith separates services somewhat cleanly then you can run them on every node and not even touch the part of the codebase that's not related to the current task.
I wasn't talking about the cost of touching the codebase, but rather running a monolith horizontally with an overhead in terms of CPU-, disk- and RAM-usage.
For big companies it might me a miniscule difference, but for smaller companies it can be a deal-breaker.
For big companies it might me a miniscule difference, but for smaller companies it can be a deal-breaker.