How much do banks sell debt for?

Could you elaborate on the process of how banks sell debt and what factors determine the price they can command for it? Specifically, are there any industry standards or benchmarks that are commonly used to value debt securities? Additionally, how do factors such as credit ratings, interest rates, and market conditions impact the pricing of bank-issued debt? And finally, what role do investors play in this process, and how do they evaluate the potential returns and risks associated with purchasing bank debt?