If you're looking for a new gaming mouse and are after something that offers more than just a couple of thumb buttons, Razer's Naga Trinity comes with a choice of three grips and is currently £64.98 on Amazon. And while it's boasting a saving of £35, the historical price of this particular gaming mouse states that £13 is a more accurate figure.
With a similar size and feel to the Hex, the newer Razer Naga Trinity is small and comfortable and has a high-quality sensor (16,000 CPI) as well as three interchangeable thumb grips. This is great as it means you're not limiting yourself to a single button layout. Each of the grips snaps into place with strong magnets and you can easily switch between them to suit the needs of any game. The MMO layout offers 12 buttons, the MOBA has seven, and there's one with two thumb buttons if that's your preference.
This is the mouse I use myself, having upgraded from a Naga Hex a year or so ago. Never one to embrace change, I tend to stick to the MOBA thumb grip as it's the layout I'm used to. If you are upgrading from the Hex, be prepared for a slight difference—the MOBA layout has seven buttons rather than six, and while I don't notice the difference now, it takes a while to retrain your muscle memory with the slightly altered button placement.