Hoser-

Again, Welcome to the site!

For holly-jolly shooting ammo - you'll find 'cheaper' ammunition for the 30-06
The '06 will be lighter and it will recoil much less.
It will be all you need for anything you've spoken (elsewhere) of wanting to hunt.

The 9.3 will also handle any/everything you've said you'd hunt, and it will do it with more energy.
That energy will cost you in terms of recoil, rifle weight, and money every time you pull the trigger.

If you're handloading, the difference will/can be less.
If you're looking at a life of shooting factory and/or custom ammunition, the additional cost can/will be substantial.

Also -- as noted elsewhere -- if you're looking to get a load put together for 'no-lead' hunting areas (like the restricted California Condor Zone), get that load together and put it aside for your hunts.
Such ammunition is expensive, and some would say (even with NF or GS bullets) that barrel life expectancy should be considered shortened if the rifle will only see copper bullets.
Re-barreling a double rifle will cost you thousands of dollars.

Your practice/fun/'rest of the world' hunting ammunition can/should be either jacketed softs or cast bullets.
With cast bullets you can shoot ON THE CHEAP - especially so with the 30-06

Do a life-cycle costing of your planned ownership/use of a double rifle.

There's some great deals to be had, especially lately.
It's important to be thorough in your decision process, so that you get WHAT YOU WANT, also that you get something that you can live with.

Cheers
Tinker