IMHO, were my current arsenal not so well stocked, I would gladly spend the small amount of cash for the Rossi. I would most likely get either the 223 or the 7.62 x 39 because those rounds are in mass circulation in civilian and military use. Here's my philosophy:

From a survival perspective, it would pay to have at least one firearm that can handle high power rifle ammunition you would be likely to find if the bubble ever went up and we were reduced to an anarchist or fend for yourself type society. Even a single shot version isn't a bad choice, as with one well placed round, you can re-equip yourself with better, yet still be able to issue that same firearm to someone else you are willing to help out (this was a big deal in WW2 for the french resistance when we dropped heaps of little 45 acp sheet metal pistols for them to do exactly that with). Even if you otherwise would use the firearm seldomly, for the price it seems well worth the investment. Also, such a firearm can be a very useful tool in properly educating new shooters with. Either of the recommended rounds are much more managable than standard high powered rifle rounds, yet still well capable for the sort of training a new shooter needs. The gun will likely be lighter and smaller than it's repeating counterparts, and therefore easier to handle for younger marksman, while still being practical enough for them to take to the field (7.62 x 39 being roughly equivalent to a 30-30 with the right bullet).

With a suitable telescopic sight mounted atop the firearm (your basic Tasco 4 x retailing for around $50 or so), it if quite functional as both hunting firearm based on the cartridge selection and for more serious survival issues.

I've used an NEF in 223 for varmint hunting, with a similarly equipped scope, and had a good measure of success when I did my part. You are not likely to get a following shot very often, but I never needed one. The NEF is a similar break action single shot, and I would compare the quality of the Rossi to be only marginally less than the NEF is, at worst. More likely they are on a par. There are an awful lot of single shot Thompsons and Rugers out there in use today, and whether it is a falling block, rolling block, break action, or muzzleloader, they do seem to get the job done about as often as any repeater does. If you think a break action takes too long to reload, try stuffing the muzzle sometime. I can spend most of a good day at the range shooting 30 rounds out of my 50 cal at 100 and 200 yards. It is a most satisfying exercise in marsksmanship and control.

308 does make a more suitable hunting round, but unless you intend to make this your primary hunting firearm, I would stick with a caliber that is more likely to be enocuntered while in scrounge mode. While not legal in most places, a 223 is quite a capable firearm for harvesting deer sized game, as a number of my "tribal" friends have attested to.