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.
1 The EPA's Installation and Operating Cost Table lists how much a radon mitigation system should cost based on the type of foundation.  Operating a radon mitigation system costs from nothing up to $700 per year. Many radon mitigation systems have fans that require continuous electric power that can add to power bills.