John K Jordan
It might depend on the car. The front bearings on my Dodge diesel truck were a major operation and big cost. I do know that if you hear any bearing noise you might want to fix it quick, but you know that! I once had bearings noises start on the interstate and the bearing was destroyed in just a few miles of driving to the next exit.
I had a front axel on my 4wd tractor come off and sprinkle steel balls on the ground. Now I periodically raise the front end off the ground and grab the wheels to check the bearings. You can do the same thing with the car - jack it up and check for play and noise or gritty feel while rotating the wheel while applying pressure in different directions.
BTW, I always buy a complete service manual for every vehicle, new or used. They are expensive but this has saved me a bunch of money over the years since I can then fix almost any problem myself.