Found this while looking for a good mouse for both daily use and gaming. The DEX version is more suitable for right handed users who find the regular version too small to hold comfortably.
Otherwise, the regular version is $159 delivered which is also a good price. Specs are identical. Here for Logitech page link.
One thing worth of a note is it uses an optical switch so no more doubleclickism.
If you have discounted GCs handy and/or price beat, it's even a better deal.
I can't find $159 one…