If you love a gaming mouse with a ton of programmable buttons, Amazon has Corsair's weighty Scimitar Pro RGB MMO on sale for $50—the lowest price we've seen recently. Weighing in at 147g, it's heavier than your typical gaming mouse, and is suited for MMOs over FPSes.
The 12 mechanical side buttons are convenient for mapping all your skills for your Red Mage in Final Fantasy 14 or undead rogue in vanilla World of Warcraft. While not as versatile as the Razer Naga Trinity's swappable side button arrays, the Scimitar's ergonomic design might sit better in some hands; the mouse's side buttons can slide back and forth up to 8mm so that they are comfortably within reach regardless of hand size.
The Scimitar also allows for on-board storage for up to three profiles, which means you can save macros on the mouse itself and never worry about losing your favorite skill rotations. If you don't regularly use an MMO gaming mouse, the side buttons do take some getting used to—you will misclick since they are packed-in together tightly. But once you do get used to them, they are a godsend outside of gaming if you like to hotkey commands for editing or other productivity software.