Dang that's an expensive install.
Let's assume a 4 hour install (if they actually take this long, they shouldn't be working on cars for a living).
Let's assume a $65 per hour rate.
We're at $260. Let's assume an alignment and that's $50 more. So $310.
That's about an average price there. I know plenty of places here that will do it for less. But really, it's not that hard to do yourself.