Looks like I need a new RR wheel bearing

At 97k miles on my 2010...

I started hearing a faint metal-on-metal noise on the highway a few months ago and knew it wasn't the tires because they were only a couple of months old. Lifted up the rear last month to check and found that the right rear wheel bearing was making a noise like it was full of marbles, so that was my first clue. Took it into a good local shop this morning before work and they confirmed that the RR wheel bearing was the only thing making any discernible noise when they ran it through the gears while up on the lift. They did say I must have caught it early because the noise isn't as bad as what they normally hear when customers finally notice something is wrong.

I checked the diff fluid level last weekend and it was fine so I don't think the bearing failure was caused by a leaky axle seal and loss of lubrication. I thought about replacing both rear bearings at the same time but it doesn't save on labor so I'll replace the right one now and see how long the left side lasts - maybe the failure of the right bearing is a fluke.

Quoted me $615 for the job which isn't too bad considering the stupid bearing assembly is a $300 part (forgot to ask if that's the Toyota or aftermarket price). I haven't called the dealer for a price quote yet although I'm sure it will be closer to $1k. I replaced the front wheel bearings myself a couple of years ago but I know the rears are more than I want to deal with.

What say ye?