Do you have a few friends who ride? If so, it might be worth looking into a tire changer and static balancer. I use a NoMar Tire Changer and static balancer which is safe for expensive wheels. In your case, the pricing reflects retail tire price with $45 installation (or discounted tire price with $135 mounting/balancing fee), give or take depending on your street price/sales tax/GET.
The tire you specified has a normal retail cost of around $302 IIRC. On sale at places like Cycle Gear and Revzilla (same parent company) for $215 right now which is almost closeout pricing IIRC. This price may reflect the intro of the Road 6 which is similarly priced, albeit likely as an introductory price instead of closeout.
For reference, I would have paid about $230 for the tire you were quoted, installed. That is with me mounting/balancing the tire. HTH
Edit: pricing