Missing school days

Our son is starting kindergarten in a couple weeks. One of the biggest change I'm realizing is the school calendar year. Up until now we freely have him miss pre-k depending on when our travels are. This coming year will be the first time we are looking at a proper spring break.

For vacation planning everything is a bit more expensive during spring break naturally. We're leaning towards having him miss a week of school potentially to save on some travel costs. Specifically looking at a cruise.

What do y'all think of that, and for dads of older children, when does missing school become more crucial?