Alan,

I have been collecting British sporting ammunition for a long time and 600NE's are pretty common with the Kynoch HS. It all depends on the headstamp, condition and how much you want it. You should be able to pick up a Kynoch headstamp version for $35-50.

Eley HS around $65-80

No Headstamp-$200-300

Jeffery Headstamp-$300-700

Corbin