How much does a new compressor for a home ac unit cost?

Quite a bit. There is lots of work involved with a compressor changeout. Ex. The refrigerant needs to be removed. Then the compressor needs to be changed. Chances are there is acid in the lines so that needs to be taken care of. After the compressor is in place, the unit has to be nitrogen charged to check for leaks. Following that the system needs to be pulled down into a vacuum. Then refrigerant needs to be added. Chances are this unit uses R-22 so that alone will be costly. If you are looking to get this done for cheap and you actually find a hack that will do so, prepare for major problems down the line. And then have fun finding the hack to fix it again.