Turn the water off. Take off the handle. Remove chrome faceplate and escutcheon. Remove bonnet nut. Pull out the cartridge. The cartridge has 2 main pieces. Separate them to get to the seats and springs.
Most are charging $1200 because they have a license, have to have worker’s compensation and general liability insurance, pay payroll taxes, pay for advertising, pay for continuing education, etc. what happens when a “bargain” goes south and floods your house?
St. Mary's hospital in Athens is almost always hiring. my wife has been there for 17 years. Good place to work and great benefits. Hope you find something soon!