As you can tell, a loaded question. Like mentioned, $500+ You will always find other things that need done or replaced. Where does it start and stop!
Post number 15 is right about labor times. Now these are average times for experienced mechanics in this type of work. Not typical actual repair times. Meant as a guide to help you compare from shop to shop on costs.
Are you mechanically inclined and would like to do your own work when possible ? No matter, download the proper Factory Service Manual for your car. This will have most of the info and illustrations on doing most repairs on your car. Every one should have one.
If you decide to do it your self, it is always best to work with another person. 4 eyes are better than 2 especially if they have experience on this type of work.
A clean workspace, just basic hand tools and a quality torque wrench. Buy quality parts and like some members have said, this is the best time to tackle all o the related items while they are removed. Belts and hoses are items that deteriorate with heat and time since they are made from rubbers that harden over time. Coolant and oil/filter change time. Check you brake fluid and transmission fluid conditions as well. If they are more than5 years old consider replacing them as well. Just like keeping your body in shape.
GM made some of their gears with fiber on the sprocket teeth to run quieter and those would get brittle and fall off....into the oil pan.....into the pick-up screen, reducing or eliminating oil pressure.....