Right off the bat, let me say Microsoft's "Wireless Comfort Desktop 5050" package consisting of a wireless keyboard and mouse is not a gaming accessory bundle. So why highlight it here? Well, while it's not designed specifically for gaming, these parts are ergonomically built, and incredibly cheap right now.
Lenovo is offering the package for just $19.34. That's a $50.61 savings over its list price. It has not always sold for the full MSRP, but it has generally gone for north of $55 on Amazon when it was in stock (it's not right now). And at both Best Buy and the Microsoft Store, where it is in stock, it's still listed at full price.
Microsoft Wireless Comfort 5050 Keyboard And Mouse | $19.34 (save $50.61)
If your dedicated gaming keyboard is cramping your wrists and your style, try this inexpensive and ergonomic bundle on for size. At this price, it's worth considering as a backup, or swap out the keyboard when the gaming session ends and work begins.View Deal
If nothing else, you're getting a backup wireless keyboard and mouse for under $20, and from a name brand no less. You might even find that you like the keyboard enough to make it your daily driver. It is not of the mechanical variety, which is a bummer. However, the curved design is indeed comfortable. For many years, I used a Belkin ErgoBoard with a similar curvature until I eventually wore it out, and absolutely loved it.
This one is shaped a little different than the ErgoBoard, but is "ergonomist-approved," for whatever that is worth. According to Microsoft, it is shaped to encourage a more natural posture, aligning your arms, wrists, and hands.
You will have to make do without amenities like backlighting and profile/gaming keys. However, you do get a bunch of dedicated media keys, customizable shortcut keys, a number pad, and wireless connectivity. And the bulk of user reviews are generally positive, at least for the keyboard.
The bundled mouse is less interesting, especially for gaming. It has just two primary clickers and a scroll wheel. There is no mention of the DPI, only that it uses Microsoft's BlueTrack technology "which combines the power of optical with the precision of laser for remarkable tracking on virtually any surface."