What I have read it's that is an evolution of 440c, used in europe, specifically Germany.
440c with a plus on cobalt, so it's called N690co.
N695 is equal to 440c, and N690co it's 440c plus cobalt.
I have knives in both steels.
I have a folding hunter from fox with n690c and agree it takes great edge and it's easy to sharpen.
About comparing it to 154cm, I have a few with such steel, and agree it's similar.
Don't own any vg10, the only knives I have contact with such steel is spyderco, and haven't bought anyone, just s30v, so can't say.
Finally, as stated above, you can´t put a price tag on it unless you give us more information, like brand, model, or is it custom, pics, etc.
The steel is above average, being average aus8 or 440c, or 420HC.
If you take the bar a notch up, then is decent, being decent vg10.
there is a thread in bf right know called "junk steel", where the op asks about wich steel you won't buy just based in the steel.
Lots of info an comparisons there.