definitely a carcano. as for value, I wouldn't even put a value on it. the last time I was at cabelas there was an entire rack of them in the used gun section(well over 2 dozen rifles). many were running from 275-400 dollars depending on condition and caliber(I'd place yours at around 300-350ish).
I guess Cabela's is being optimistic. I have yet to see any Carcano that's worth anywhere near what they are asking.
Carcanos in this neck of the woods are $125.00-$200.00 tops. I wish I could get what Cabela's is asking for my Carcanos.
As far as en bloc clips are concerned, there are plenty of them available on such sites as eBay, Gunbroker, etc. Tahunua, I don't know where you live, but clips are common around here.