The major advantage that the internet houses have is that they don't collect sales taxes. GC doesn't have that advantage since they have a brick and mortar store in so many cities, and when they do, they have to collect sales taxes on orders from those states. Other than that the prices are about the same, except in very small stores. If they start requiring the internet houses to collect sales taxes, we will see a rise in the number of successful local stores. For example, if you bought a $2500.00 keyboard in a local store in Arkansas, you would have to add on as much as $250.00 for taxes, according to which county you lived in. If you bought from Musicians Friend, you would pay no taxes during the transaction. They have few local outlets so that would apply in most cases.
The same applies to Amazon.com.
As it is now, many go to the local stores to test instruments, and then buy them from the internet houses or a business like Amazon.com.