This method also requires some sort of key store (see above). However, if you want to maintain just one key, each key rotation will require you decrypt data with the old key and reencrypt with a new key. Again, it depends.
Although the Razer DeathAdder Chroma technically carries a suggested price of $70, it's often available at a healthy discount. For now you can grab it for $49.99 on Amazon or around that price at other big box retailers. Durinf extreme sales events like Black Friday, the DeathAdder Chroma can drop to as low as $35.
Radon price: $4/m ?? I'm doing some research on Radon. I have to put together a PowerPoint presentation that describes its origins, properties, characteristics, etc. (Each student was assigned a different element.) One piece of information I'm required to report on is current price to purchase a sample of the element.