We updated our kiddo's bathroom by replacing the vinyl floor with ceramic tile. We liked the vanities and tops as well. But they screamed 80's with the whitewash stain that had yellowed. We stripped and painted them matte black, kept the original grey countertop, and replaced the faucets and hardware. We also had the solid mirror on the wall, so we applied painted black molding around it for a framed look. Very happy with the look, and it was not too labor intensive.

Paint them.

You can change the doors and refinish the cabinetry.

Refacing costs as much as replacing. If they don't provide enough drawers and storage, replace them. If they are the newer adult height vanities and not the old short kid height, just paint them.

Reface them for a new look without the hassle and inconvenience of replacing.

We had some cabinets repainted and doors replaced with better hinges.. The carpenter who made the doors also added trim to the cabinets to raise the height before the new stone counters, sinks and hardware were installed. We love them and we saved a ton of money. The labor was very reasonable (which is not always the case). It depends on your area.