The display enclosure ranges from $11 to $40 on eBay and Amazon (The entire display assembly including the LCD panel, etc. is $120-$180). To replace it requires the entire display assembly to be removed and disassembled, which means the laptop has to be disassembled as well. This is a time consuming repair and likely labor expensive. This PDF, http://www.hp.com/ctg/Manual/c03943414.p..., has the directions for disassembly (pages 55-63 for the display assembly itself).
I can't tell if any other parts were cracked from your question, but replacing any other parts such as the palm rest (which wraps around on many models) isn't likely to add much if any to the labor cost.
Some local computer repair shops will do this type of repair, I do this type of repair myself. The labor costs vary so much I can't guess at an estimate of the labor in your area. I think $150 is fair, but is likely much more.