Good luck finding one. The demand is high on these rifles and they sell out as soon as or before they come in. Some folks order a half dozen on spec and they show up in auctions, buy-it-now, and classifieds at high prices.
The demand is such that used ones, if you can find one, sell for nearly the price of new ones. Just a point of terminology, a firearm once sold at retail is no longer legally NIB (BATFE Rules). Only the first retail owner has warranty privileges. Some manufacturers don't check to hard about that. A seller's NIB claim may be true in the practical sense but legally it would be a used gun, perhaps As New In Box, Mint, etc.
Anyway, here's my track on the 1894C .357, I sure love mine:
Marlin 1894C Rifle in .357 Magnum,.38 Special, Plus P, 18 in Bbl, .38 Special, Plus P . Bluebook of Gun Values (30th Edition) indicates between $365 in 98% condition and $465 in 100% condition for this gun. I have 49 recorded prices for this model gun from $325 to $705 over a period of 4 Yrs 6 Mos ending October 26, 2009. The average price as of that date was $491. No refurbs, no refinishes, regular sights, all represented as 95% or better, no distinction for import location or engineering revision, if any, no special editions, no distinctions for box, papers, tools. Current or last MSRP is $591.
Here's how the data trends chart out. Notice the price trend is at about $560 as of October 2009 for
used rifles: