You get what you pay for. They are built by the same people out of the same factory. I am sure if you go detailed item for item you will see the $10k in differences.
A couple people have asked similar questions (Bounder vs. Vacationer). I don't recall anyone actually posting back the differences. May want to also look in the Fleetwood forum for more info (http://www.irv2.com/forums/f107/
I know the dash is different. I thought some of the color options were different too. Check options available.
Check the OCCC of comparable RVs.
I laughed at a salesman one day at an RV show when he was comparing a 22k GVWR coach with a lower rating coach saying they were EXACTLY the same.
I explained to the buyers as to what the main differences were. If a salersperson's lips are moving...