Replace the medicine cabinet for $100, new light fixtures $100, new faucet $75 and a new vanity $300. Existing grout between tiles can be lightly scraped, re-grouted and buffed which will make the old tile look brand new. Replace the tub caulking with fresh white caulk. Install glass shower doors. French doors add a lot of elegance for $500. Total, you have spent about $1,000 without replacing any existing tiles. Bathroom updates are key to selling your home.