Probably warped brake rotors. They can be taken off and machined true or just replace with new rotors.
I have found that new rotors are in need of turnig even though they are NEW. They tend to have not been machined with tight tolerances because they are mass produced. You may not feel anything in the break pedal but, if you do you have to take them off and do all that work AGAIN.
Disks out of round, worn or warped will cause the brakes to vibrate. You need to have the rotors ispected and machined,if there is enough thickness let on them. If this does not fix the problem, you need to install new rotrs.
If your rotors are worn you should replace those as well. Worn, warped, or glazed rotors will reduce the effectiveness of your brake pads and possible wear them down faster. As far as the possibility of doing so, sure but it's not recommended. Just to add a comment, depending on the rotor thickness, the rotor surface should be machined to remove the glaze or warpage before installing new pads. Machining of a rotor surface reduces the thickness. If a rotor surface has previously been machined the rotor may need to be replaced.
As long as your rotors are not warped, or you have not let the brake pads wear to the point they defaced the rotors, there is no need to change them. Just install new brake pads. Rotors can last the life of the car.
Many dealers charge any where from $210 - $350. It all depends on the rotors, if they can be machined then it will be toward the lower end.
No, unless they are rusted.
More than likely you have warped rotors. Have the rotors and brakes inspected. If the rotors are not too bad and have not been turned before they can be turned and trued and used again. You will also need new brake pads.
One of the two brake rotors on the front is warped. You can either buy new ones or get them machined if they aren't very old. sounds like one of your rotors is warped.
Typically rotors come from the factory covered with a waxy material to prevent rust. Yes, it's a good idea to remove that material before using the brakes.
There was a lot of squeaking while braking when my car needed new rotors.
No you do not have to get new rotors just have them resurfaced. If they are to much warpage then you may need new ones. I would try getting them resurfaced before you replace them.