I've seen a value pack fairly recently at my local Michael's (link below to show image but item is out of stock online):
ColorBox� Cat?s Eye� Value Pack
I have a few in the chalk ink formula. At a recent convention, I bought some more + some reinkers at Gary Burlin's booth. It seems you have need a re-seller tax I'd to create a log-in so I don't have links.
As mentioned previously, Frantic Stamper is a good source.
Good luck and ...
Happy Crafting!
Tina aka TeeGeeDee
PS - I personally do not like the work queues because I like a cover for each pad.