The car has a number of bushings so which ones are being discussed?
Before blindly assuming the dealer is robbing you blind you should consider this.
An aftermarket bushing may be available on the cheap. However, the dealer may be using factory OEM parts and this mysterious bushing may be part of an assembly.
In this case the dealer may simply not be able to obtain a bushing only and may be required to purchase the assembly with bushing installed.
In spite of the perception, those factory OEM parts are not sold to the dealers at discount, wholesale prices. The dealer pays dearly for them.
The devil is always in the details.