The below thread talks a lot about this, and also ends with a great solution which is a Jones X-Pipe mid-muffler that helps quiet down the exhaust for people who have added headers and wanted to tame it down.
https://www.camaro6.com/forums/showthread.php?t=576096
OP - You're right the cost of exhaust is ridiculous now. That isnt going to change though, so I decided to just accept it and make sure I like whatever I spend money on.
Like you, I dont love the stock suitcase, but for me it is sound and not looks. When I get my car next year I plan to either add the Borla S-Type Axleback marketed for the SS(yes it fits the ZL1 pefectly) or AWE's touring edition axle-back exhaust. AWE doesnt offer valves, but it is $1,000 cheaper at $1400 and has NO drone, it's a great option.
I will add headers later once I have put 5k miles or so and ready to tune the car, but I already know without a doubt I will need to add the mid-muffler at the same time as the headers.