Amazon is currently offering a 5-Pack of Lifelong Rollerblade Style Chair Caster Wheels for only $29.99. They retail for $39.99, although in reality they're always "on sale" for about $35.

A set of five replacement caster wheels are now available from just $35 or approximately £25 providing early bird backers with a 42 percent saving of the recommended retail price.

Thanks to their constant contact with the ground, it's inevitable your task chair's casters will get dirty and gummed up with bits of hair, office debris, and other junk. Rather than shell out for ...