Hi, I think you may be able to get it slightly cheaper. As far as doing it yourself, if you have experience with soldering copper pipes, then yes you can do it yourself. If not, then do not even attempt it. For those that have experience with soldering copper pipes. 

1. Shut off the main water to the house.

2. Turn on the hose bib (Frost Free Faucet) to drain the house water.

3. Open a faucet in the highest level of the home to vent the water and assist the draining.

4. Cut out the frost free faucet with a pair of pipe cutters.

5. Sand the end of the copper pipe and clean the couplings and the inside of the hosebib.

6. Use a small amount of soldering flux on the fittings and the pipes.

7. Attach the new frost free faucet with a coupling and a piece of copper pipe.

8. Heat the bottom of the fitting and then touch the solder to the top of the pipe/fitting joint.

9. Wipe the fitting with a cloth.

10. Let the pipes cool.

11. Turn on the house water and close the faucets and check your work for leaks.

12. Make sure the pipe grades slightly to the outside of the home.

13. Tip. You may get draining drips of water that continue to drip while you are soldering. A old plumbers trick is to use a piece of white bread. Ball it up and put it in the pipe to stop the drips. Also, home centers sell a ball that can be used for the same purpose. The bread and the ball both disolve in the water after the water is back on.