The blades are quite a bit more common than the scabbards, though they surely don't show up every day.

The rare scabbard is of the simple metal hook style which swivels 360°. Also, the mouthpiece is VERY slightly trapezoidal, but enough so that the blade will only go in one way. No other Krag scabbard is worth a premium, so don't overpay for an 1894 blade in a later scabbard.

What is the price of the set? 

I was happy to pay $225 a couple of years ago for a decent blade, and scabbard having two significant dents. I've seen other blades since, but not another "keystone" scabbard.

The problem is going to be finding the right scabbard. Most were modified or just plain used up. I'd follow gunbroker.com, and look at every Krag bayonet at every gun show I went to.

I suppose I'd go $150/$175 or so for a decent/nice 1894 bayonet, even figuring to discard the scabbard if need be, or use it as trade later - maybe some day you'll find a late blade in an early scabbard. Also, for that money, the grips and rivets must be the original flush-polished ones. A re-gripped 1894 is worth no more than any other date.

In any event, you'll have to dig - I had my 1892 rifle for many years before stumbling onto the bayonet. FWIW, I don't subscribe to having to have a bayonet for every rifle in the collection. These days that can run the cost way up.