Is this too good to be true? SM57 fakes??

Probably fake tbh. I'd get the seller to 1, take a picture of the logo on them- the fakes often have a raised 'R'. Secondly, a pic of the mic unscrewed will allow you to tell. I picked up a fake for £15, its got a much higher output than the real ones, surprisingly wasnt the worsed sound in the world either.
 
Anybody selling 3 SM57's for $135 is out of their mind. They go for $99 each brand new in the US. They'd be ripping themselves off tremendously. That's not even a whole THIRD of what they COULD get for them.

~e.a