i won't remove them unless I can put the car on a hoist, I am just afraid of dropping a car on the exposed brake system.
I don't do it just cause of the risk, and the liability if you don't tighten them properly. But I would charge another $100 dollars or so to do it
If you put a stand under the frame before removing the wheel there is no chance of the hub hitting the ground. Leave the jack in place for added support.
I have a 3.5 ton jack with 6 ton jack stands do the car is not going any where I have torque wrench and a chart with the manufactures torque settings for lug nuts so there so no problem with putting them back on
One thing, if you are going to be doing alot of European cars that have lug bolts instead of lug nuts it would be advised to get yourself a wheel hanger. You screw them in place of one of the lug bolts and then put the wheel on that to help support it so you can get the other bolts in and not have to struggle with holding the wheel up and trying to get the bolts lined up. Also look up the torque specs on the bolts so you know what to torque them down to. But, $100 sounds fair for 4 wheel removal and cleaning.