I just had the front bearing units replaced on a 2001 Dodge 1500 4X4. A little under $400 for the hubs from O'Reilly, and $364 at Tire-Rama for the installation. While they had it apart, I had them replace both front axle shaft u-joints.
I have driven some very old vehicles in my life, and I have never had a rusted out oil pan! My son is driving a 1994 Dodge Ram 3500 CTD with 279K on it, that was used in California and Montana for most of its life. It still, as far as we know, has the original oil pan.
Yes, definitely, find a better mechanic!