Sako still make ammo for them, and it is still listed on the website. It is an order in proposition, and can get costly. You can get it though.
Personally I always wanted a 7X33, its a sweet little cartridge.
As for a value, its tough for me to say, this is going off pretty much the top of my head, but maybe 500$s. I am sure some of the guys in the hunting forum could give you a far more accurate price, but here in NS, I would expect it to go for about 500, maybe less.