Even though proficiency with Morse Code is no longer required for getting an Amateur Radio license, young students often find code a fun activity. Fancy Code Keys can run in the hundreds of dollars and even a cheap plastic based “bargain” key is $12 to $20 each, even on eBay, and you have over 25 students!
The Clothespin Key was designed with price and durability in mind. In addition, it allows the students to assemble their own keys. Here is a typical price list:
As you can see, if you buy in bulk, you or your radio club could easily cover the cost for a class of 25 students by passing the hat at your next club meeting. You will notice the battery is over ½ of the cost for the key, so if you make it BYOB (bring your own battery) the keys can be under a dollar each.