Cabinets are usually the single largest number on a kitchen estimate, and replacing them drags the rest of the project along with it. New boxes rarely land in the same footprint, which means the counters, the backsplash, the plumbing, and sometimes the flooring all move too. So the first thing we do on a kitchen walkthrough is work out whether the boxes you already have are worth keeping.
Three things decide it. First, the box construction: plywood or solid-wood boxes are worth refinishing almost every time, while particleboard boxes that have swollen around the sink are not. Second, the layout: if the kitchen works and you only dislike how it looks, refinishing is the obvious answer. If you are moving the range or opening a wall, the cabinets are coming out regardless. Third, the doors: warped, delaminating, or badly water-damaged doors can be replaced individually onto sound boxes, which is still far cheaper than a full replacement.
When refinishing is the call, the process matters more than the paint. Degreasing comes first, and it is not optional in a kitchen, because cooking oil in the finish will reject anything you put over it. Then scuff-sanding, then a bonding primer suited to the substrate, then a sprayed cabinet-grade finish rather than brushed wall paint. Doors come off, get numbered, and get sprayed flat so there is no brush texture on a surface you touch every day.
Done that way, refinished cabinets are difficult to distinguish from new ones and typically cost a fraction of replacement. Done the fast way — a scuff and a coat of wall paint straight over the grease — they start peeling at the handles inside a year, which is where cabinet painting got its bad reputation in the first place.
If you are weighing it up, get someone out to look at the boxes before you price new ones. It is a fifteen-minute conversation that occasionally saves five figures.