Dear Gagetman,
The .356 Winchester was a failed marketing concept and cartridge, brought out by Winchester back in the late 70s or ealier 80s, to try to boost the lagging sales of its Model 94 carbine, by creating a round (somewhat similar to the .358 winchester) that would fire in the relatively light action of the Model 94. At the same time, they brought out the .307 Winchester, to create a cartridge with the ballistics of a .308 that could fire in the Model 94.
Both cartridges were a dismal failures, and the rifles were only sold for a couple of years. I believe that factory ammo is only available in one one load for each cartridge, and you may have a big problem finding those.
The rifles are relatively rare, because they were a big failure. (I do not believe that this makes them collector items in any respect.)
The problem with both rounds was that they had to be made with flat nose bullets, to safely fire in the Model 94, and this of course ruined their ballistics and power out past 100 yards.
When you buy a rifle like this, considering the problems, it is hard to say that anything is a bargain. If you are also getting 10 boxes of ammo with it, and don't shoot more than ten shots a year, $250 might be a bargain.
Hope this helps.
Big Paulie