I've used a G2 with a 21/2.8 extensively. That camera has advantages that the Bessa can't touch. .. auto loading, auto advance, auto focus, very fast metering, exceptional low light auto, decent flash close up.
Though "advantages" are truely in the eye of the beholder...
For some RF users, including myself, those go against the entire RF workflow.
The G2 is always in the back of my mind. Wonderful lenses and relatively cheap to have. I'm afraid most of the use of 21mm is insides of churches, the G2 is noisier than a manual focus camera and I suspect that would be a "problem". It's also the kind of camera that is not going to last for the next 20 years or so, and when it breaks, my investment in lenses will be in danger. I'm especially concerned about the many motors inside it: a motor for focusing, a motor for moving the viewfinder (zoom and parallax correction), a motor for film winding. Electronics inside a camera can last for many decades without any problem, but I suspect motors are not that long lived.
A LTM or M-mount investment is something I would do with less worries. But I do go on checking auctions for G2s.
If you really want to do this on the cheap and have a carry-around camera, look at the Vivitar Ultra Wide & Slim. The 22mm lens is quite good, although you're limited to one shutter speed. Works best with 400 speed film.
If you just want a superwide lens, this is the one to get. Slips into a pocket and costs less than $10.
I have also looked at some Zorki. Most of them are outside the EU and I would like to avoid all the custom office procedures, so I tend to buy only in the EU. I would certainly buy a Zorki if the camera is somehow tested. It's one of the many options. I would be using it mostly with an external viewfinder so a replica of the Leica III series would be adequate, but it must be cheap. Russian cameras are not renown for quality controls and uniformity of production, I fear buying a "lemon" so I can buy something with CLA by some reputable seller, or something that must be cheap enough to run the risk. Also they are very old cameras now and although I can trust an old Leica I don't know how much I can trust a 60 years old Zorki or similar.
The Vivitar Ultra Wide & Slim it's not an option I would consider as I need professional quality (quality good enough for stock photo agencies).
EDIT: I've written an email to a Roman repairer requesting his opinion on the future serviceability and availability of spare parts of Contax G2 cameras, I hope he'll be kind enough to answer, in case I'll let you know.
The repairer answered my question but in very generic terms: Contax is out of business now (I knew that), so there is not guarantee (I imagined that a long ago), but generally speaking G2 are cameras known for not giving problems.
The answers I expected were of the kind: yes we can open, clean, lubricate and up to a certain extent repair a Contax G2. We have a number of G1/G2 bodies to cannibalise in case of need. We can even reconstruct broker motors ourselves;
No we don't service Contax G2 because they are too difficult to find spare parts for..
That's less than €300 for 15mm lens, viewfinder, camera and never-ready case. With a lens cap and a Nikon strap.
I was checking yesterday that my Yashica T3 (1989) still works perfectly and so probably motor fragility is not something to be too worried about. But then I won the auction so that means in this life I will never buy a Contax G2, I suppose.