How much does it cost to convert ETH to WETH?

Could you please enlighten me on the cost involved in converting ETH to WETH? I'm quite interested in understanding the financial implications of this transaction. Could you elaborate on any potential fees or costs that I should be aware of? Also, is the conversion rate fixed or subject to fluctuations? And if so, how often do these fluctuations occur? I'm trying to get a clear picture of the overall expenses involved in this process. Thank you for your time and assistance in clarifying this matter.