NCIX has the Microsoft Natural Ergonomic 4000 Keyboard USB on sale for $27.99 (save $22 off). However, you can price match with Memory Express who are selling it for $44.99 and they’ll beat 25% of the difference.
Shipping is extra, but should be only about $4.99
If you need something more basic NCIX also has the Microsoft Comfort Curve 3000 Keyboard on sale for $10.99 (save $19 off). You can price match again with Memory Express who are selling it for $14.99 saving a $1.