Reminder: The merge will NOT affect gas prices

Blockchains have three parts: a consensus layer, an execution layer, and a data availability layer. When you submit a transaction and pay gas you are paying for use of the execution layer.

The merge is an upgrade to the consensus layer. It swaps proof of work consensus for proof of stake consensus. This will reduces energy use, but because it's not the piece you are paying for when you pay for gas, this change won't affect gas costs.

Cheaper execution layers already exist though (Arbitrum, Optimism, etc.).