Welcome!
It’s great that you have an idea what you want before making the plunge. My bikes run the gamut from racy to utility and I have found my comfort zone so I will narrow down the fleet accordingly.
FWIW - almost all of my recent purchases have been from Marketplace. Asking prices on CL in my area are very high (to me) and it is mostly new-ish stuff. I have also bought a few things from OfferUp with success.
Again, welcome and enjoy the ride!