Grado like mids?
I'm going to ignore your price and post anyway.
The Koss Pro DJ100's driver reminds of the an improved SR-80 driver, but without the fatiguing highs and with more bass. Not excessive mid-bass. Also less grainy than the SR-80.
I have a feeling that the driver of the DJ100 comes from the same manufacturer as the SR-80 driver. No, not Grado silly. I don't think Grado really makes their own drivers and I could have sworn they all came from Taiwan.
The DJ100 and SR-80 drivers look so extremely similar, but this means nothing. Same plastic housing around the driver, same size, same amount of vent holes and everything. You can take the DJ100 driver and put it into an SR-80.
So, I'm going to say the koss Pro DJ100. It takes the Grado mids I like and makes gives it a better signature. IMO though even a modded SR-80 can't compete with the DJ100, but I haven't tried swapping out the shells yet.
Of course the DJ100 will never have the treble of a Grado. With the Dj100 you sacrifice a little treble for more bass.
Like the SR-80, the DJ100 can benefit from a good amp.
I was hoping someday to find another headphone with the DJ100 driver, but I don't think it exists. It sure would be nice.