I bought one off of eBay a month & 1/2 ago - paid $190 including shipping. LOVE it. The only problem that I have with mine is that a previous owner really filed down the slot in the nut for C string - so much that the string practically sits on the first fret! I've filled the slot w/super glue to then file back down a bit to see if I can get away w/o swapping the nut out.
I believe that these go in the range from $200 - $400 & sometimes higher depending on current market & if there are other Kamaka soprano's on the particular forum of choice.
Well I can say its far from mint. I'm looking up some local luthiers to fix some gluing issues, but then it will be for sale. I will post some pics this week.