A new vanity and faucet change how the whole room feels the second you walk in, turning a dark, cluttered corner into something clean and bright. The actual plumbing swap usually takes a single afternoon if the pipes line up, though you should leave a full weekend open in case old corrosion puts up a fight. Big box hardware stores usually slash prices on bath fixtures around major holiday weekends like Memorial Day and Labor Day.
If you are hiring a plumber for the install, do not just call the first name on search. Get at least three quotes from local independent pros to make sure you are not paying double for an hour of actual pipe fitting.
That 0% intro period is a hard deadline, not free money, so make sure the math works out. If you still have a balance left when the 15 months run out, interest will kick in on the full original amount from day one.