As title said, Logitech K800 Wireless Illuminated Keyboard is $49.99 in Amazon.
According to camel, this is the lowest price.
I am replacing current K800 which I bought many years back. Finally some keys fell out. Could easily be fixed by buying keys from eBay but decided to replace whole unit and keep this as backup.
Rechargeable battery holds power very well even after many years of re-charging.