Wheel bearings are fairly common on ram trucks. I do one about every other year between my 2 trucks. I do them myself, and on the 2500 it can be a pretty big pain in the butt. It's actually a pretty straight forward job, but what happens is the wheel bearing assembly gets rusted stuck in the spindle housing. Especially if it hasn't been apart before. A lot of force and some heat was needed for me. It should be fairly obvious if the wheel bearing is getting bad, maybe not to a female though.
Having said that, $2100 for the wheel bearing installed is insane.
Also I've never heard or seen an oil pan rusted out on a cummins, let alone an 06 or newer. My 05 has rust on it, but not even close to rusted through. I live in a state that uses salt on a daily basis in winter. I find the oil pan story hard to believe.
The oil change price is high, but probably not crazy high coming from a dealer. The price should be half of that at a jiffy lube or similar.
My advice is to disregard anything that dealer said, and go to a trusted independent shop.
Maybe join cumminsforum.com and ask some locals in your state to point you in the right direction for a shop to not rip off your wife.
Good luck and thanks for the service!