$750 to replace a pressed-on bearing seems maybe a little on the high side, but not totally unreasonable. It depends on what exactly needs to be done to effect the repair. May require new wheel alignment for example. Labor rates can be in the $150 - 200 per hour range in some areas. Same as if you are hungry and want a hamburger, and the hamburger shops says it will cost $5 and you only want to pay $2. In other words if a mechanic’s bid seems too high, shop the job around to other qualified mechanics.