Mine cost right at $4300 for everything (prop, mounting kit, spinner kit) including expedited shipping.
A couple of things I did to mine after the initial install...
1) the front bulkhead had a wee gap between it and the inside of the spinner cone and wasn't as tight of a fit as I liked, so I ran a bead of RTV silicone rubber around the edge of the front bulkhead, and wrapped a strip of Saran Wrap all the way around the circumference of the front bulkhead, then put the cone on and fastened a few of the screws and let it cure overnight so the RTV would conform to the gap and fill it and the Saran wrap keeping the RTV from sticking to the inside of the cone. After the RTV cured, I pulled off the Saran Wrap and trimmed off all the excess RTV with a razor blade and now have a nice, snug, RTV-cushioned fit between the front bulkhead and the inside of the cone.
2) The two little phillips head #10 screws and the small nordlock washers that hold the front bulkhead to the prop hub don't have enough surface area contact against the soft carbon fiber face, and the carbon fiber will get eaten away under the serrations of the nordlock washer and come loose. I thought I had felt a slight vibration during a flight and after putting the airplane away in the hangar, I turned the prop over by hand, and sure enough, heard a loose screw rolling around inside the spinner. Nordlock washers need to be used only with metal, the carbon fiber of the bulkhead is much too soft to provide a sturdy enough surface for them to dig their serrations into.
I solved that problem by using two short AN3H-3A bolts with drilled heads and two AN970-3 "fender washers" and used those instead of the #10 screws. The amount of surface area covered by the large washers against the carbon fiber will spread the load out much better. I also shortened the bolts a tad with the bench grinder to make sure they wouldn't thread into the prop hub any deeper then the original screws did, and cleaned up the threads with a die afterwards, but later examination seems that this was probably unnecessary and the threaded holes in the front of the prop hub seem plenty deep to accept the length of a stock bolt. I also used a drop of Locktite Blue on the threads in addition to safety-wiring the two bolt heads together. They're not going to vibrate loose anymore.