there are lots & lots of good quality 4" knives out there.
most are similar price range to the RC-4, tho...
check out Grohmann #X107SD Outdoor Knife, factory second for $36 Canadian: http://www.grohmannknives.com/pages/clearance.html
It doesn't have the flash sheath of the RC-4, is SS instead of CS, but maybe will do what you need.
No affiliation other than being a satisfied customer (I bought 4 of 'em!)