Yeah, it's only $10 off but Brainwavz are excellent and a Dual Dynamic earphone under $100 is a bargain in itself.
These are brand new so there's not much info out there but judging by the rest of the Brainwavz range these will be pretty special.
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was blown away by the sound of Betaz, unfortunately it's broken (heavily distorted) on the second days.
And bought the 2nd one M4, but dissapointed of sound quality (I know it's personal) but can hardly distinguish between M4 and cheap earphone from DealExtreme, and the cable quality was poor as well.
So before you decide to get this, read the reviews carefully. :)
One good thing, the support from MP4Nation is awesome.