Dollar for dollar, I will always choose cutting costs (even though they aren't mutually exclusive so this question doesn't really matter anyway). I outlined why I take that stance earlier this week https://www.marriedwithmoney.com/when-a-dollar-isnt-a-dollar-the-case-for-cutting-costs/
TL;DR: Taxes make your dollar earned less than one dollar. A dollar in cost you cut, is a dollar LESS you need to survive, theoretically forever. (putting you closer to early retirement)
The key is to not let lifestyle inflation get the best of you. It's easy to think a $1200/yr raise is $100 extra a month in your pocket. It's not.
But if you cut our cable TV and reduce your cell phone bill and that saves you $1200/yr? That's actually $100 extra in your pocket.