Wow lots of opinions.., here's what I have found..,
As for pricing 16 gauge shells, try here:
sportsmansguide
Estate or Federal or Remington, and you pay in most cases a whopping .04 more per shell than a 20 or twelve (roughly). High brass heavy loads you will pay .08 or more per shell, but I've never had to use premium shells to limit out. Now IF you are shooting a flat or more of shells per month..., you need a twenty, as reloading won't do it for the 16 gauge. One person suggested 28 gauge, but the ammo for that is to16 gauge shell prices as the 16 gauge is to the prices on 20 gauge, in many cases.
Lets get back to the original idea...
Fact: one ounce of lead shot from a 20, 16, or twelve, fired at the same velocity from all three using guns of equal weight, will equal the same amount of recoil in the opposite direction (toward you). Lest we forget, Newton's Third Law "
The mutual forces of action and reaction between two bodies are equal, opposite and collinear. " In fact due to less inertia, a lighter gun (which is probably what you'd get with a 20 gauge) will recoil more. OK great, so what?
If the gun fits the shooter well, then it is a well known consensus (for it is an opinion, not really measurable) that the shooter often feels that the recoil is less. Even when that gun is shooting ballistically identical shells to the disliked gun, and the favorite gun is lighter than the disliked gun (so the recoil is actually harder) the shooter will often give the opinion that the recoil is less.
So..., percieved recoil is really the issue, and actual recoil PLUS gun fit are the factors to be adjusted.
I think before you buy, you need to test fire several different makes of shotguns of various gauges, and then decide. You may find another twelve of a different make and model is just what you need, or you may find a specific 20 gauge is just right. Perhaps a vintage 16 will be just what the doctor ordered. Only you can say.
I shoot several 16 gauges for the nostalgia, and they fit me very well, so I shoot better with them than other shotguns that I have owned. I spend about a dollar or more per box of shells than the guy with the 12 or 20. I also CHEAT by using chamber adapters sometimes to shoot inexpensive 20 gauge shells in my 16, so I opted for the 16 gauge as I know you can adapt it to shoot 20 gauge shells if it still isn't right...,
With my 16's (a Savage 311 retrofitted with screw in chokes, and a CZ) I get the best of both worlds.
Good Luck, and have fun testing the guns.
LD