The cows are laser-cut from acrylic (just under 1/8" thick). I currently have sets of them available for sale in the following colors (picture to the right shows a cow in each hue):
The cows cost $0.25 (25 cents) apiece, unassembled (there are two parts, the clear base and the actual colored cow that stands upright). You will have to assemble and glue the cows yourself at that price. Assembly is very easy (it just takes a little time and the right kind of glue). You want to use glue that is formulated for acrylic. The type I use is IPS Weld-On 16 Acrylic Plastic Cement, but there are many other brands. You should be able to find a suitable glue at any major hobby/craft store.
The 'glue' is actually a very runny, clear solvent that evaporates quickly. To assmble a Zoff Cow, insert the square feet-pegs into the square holes of the base and hold the piece upside down. Dab a small amount of the solvent into the underside of the square holes. In about 5-10 seconds you can put the cow down and go to the next one. In a few minutes the two pieces should be set tight, the solvent having cured.
Of course, read and follow any warnings on the glue packaging.
A herd of cows for a game of Zoff is 48 cows per player. So, at 25 cents per cow, a single herd will be $12. Zoff can be played by up to 5 players, so you may consider getting at least five herds.
You can get herds that are not exactly color matched to the five decks of cards in the game; as long as each player has a distinct herd color, that's all that really matters (since unplayed cows are kept in front of a player, it's easy to see who is what actual cow color, regardless of cards colors).
If you want to order cows from me, let me know how many of each color. Note, that if you want me to assemble/glue them for you, the price will be doubled (50 cents each). With each order I'll toss in an extra cow or two for you to test your gluing skills.
Shipping and Handling within the U.S. will be $10.00.
The cows can, of course, be used in other games that require cattle-bits (e.g. Agricola).