There was a post here a while back where a member had theirs replaced. I do remember being surprised at how reasonable the price was, just a couple hundred IIRC.
If you have a good dealer, they might be able to work with you on the cost if they are doing the work. My dealer has also cut shipping costs by having Jayco send a large part (axle in my case) inside a new trailer being delivered.
ETA: Okay, memory may be getting faulty with age. Tried searching a few different ways for the the thread I recall seeing, but no luck. Maybe I just dreamt it?
2011 Jayco X19H (purchased 2015)
2008 Jayco 1007 PUP (purchased new, traded for the X19)
2012 Chev Traverse LT with TP