Is it illegal to buy fake guitars?
It is not illegal to purchase a fake guitar when you know it is
fake. It is illegal to sell a fake guitar without revealing that it
is fake. That is called fraud.
Selling a fake guitar, or other item, even when you reveal that
it is a fake, may be illegal as a trade mark infringement.
If you buy an item that you know is counterfeit, then you are
aiding and abetting the counterfeiters.