Finding a shop to repair it could be a challenge. Personally I'd say $5k is on the high side. Just looking at it, I'd slap a couple new layers of glass on the back side since it looks broke though. Grind out the cracks, fill with kitty hair. Grind back down for gelcoat and patch the gel. Custom color match, or don't even gel it and squirt single stage paint over it.
The cost of material is insignificant here, even though autobody materials have increased substantially. There isn't more than maybe $200 worth of materials to be used in that repair. Might be more if you bought everything yourself.
All that said, it may sound like I'm oversimplifying it for anyone who doesn't understand autobody and fiberglass work, but it's not that technical of a repair.
Another option, search RV boneyards for a matching piece.
Now, please explain what happened, hard to comprehend how this happened. Just my curiosity...