I’d say you are looking at 10 hours of labor at a minimum, so multiply the hourly rate in your locale by 10 at least.
If you buy the motor and take it and the car to a shop for installation you are playing in a lot of “unknown” territory. This will make it impossible for the shop to give you a firm quote for the job. A very general estimate is the best you will get and costs can go way up if something unexpected shows up.
Also, the new motor has to be compatible with all the pollution controls and electronic components. This makes getting the right motor important. I think it is best for the shop to source the replacement motor. That will reduce problems and make the price of the job more reliable.