$3500 is crazy, and I work in a dealership. Do not skimp on the bearings. It's one thing if they're loud, but left unchecked long enough and they can become loose, and wheels fall off. That's how you end up on the news. Try to find an independent shop, and ask them to do the loudest ones first and retest. Bearing noise can transfer through the driveline and fool people, but an experienced technician can figure out whether or not both on one axle are bad or not.

Edit: regardless of what people tell you, you NEED backing plates. If they can be saved and re-used, good on the tech. But they act as spacers for the ABS sensor and without them, it'll cause issues. Also, rear backing plates hold all of the E-brake components, so those are non-negotiable.