Ever since we moved into our house 2 years ago, whenever the heater/AC kicked on it vibrated the floor above it (our kitchen) a bit and is a bit loud. We just thought this was how it was. We had a friend over when it came on and he said that's not normal. He suggested that it might be a drum like part of the motor that is out of balance. We had the motor replace last winter. Are these two separate pieces in the unit? I don't anticipate fixing this myself, if there is a problem but would like to be educated before I call the repair guy.

Yes they are separate units.

It is a good possibility that the cage fan/drum as you call it is out of ballance.
You will have to buy a new one and also check the motor mounts.

I am suprised that the person that changed your motor did not notice this.
I would not call the same person to do the next repair.

Thank you for you help. I feel more confident calling a NEW repair person. One last question. What's a ballpark price to fix something like this. I know hourly rates vary, I just don't want to get charged $1000 for a part that only cost a couple of hundred.

The cage is about 75.00 and labor about 1 hour since the motor has been replaced and it should come apart easy. BUT some areas charge more.