I was gonna say, "regardless, it's 100 bucks too much for LGC's", but I have no idea what your cigar taxes are like over there.
If you really like them, offer him $150 and see what shakes. I think that'd be fair, even if it's still too much. As long as you like them, ya know?
As far as the provenance story goes, I wouldn't even take that into consideration for a second. It may or may not be true, but regardless, it has little or no bearing on the value of the cigar.
Whether you like them or not has lots of bearing on the value of the cigar weighed against the asking price.