Hi Guillaume......welcome to TFF.
The Savage/Springfield/Stevens Model 84C is no longer listed in either the Blue Book nor the Standard Catalog of Firearms, so I'm going on memory on this one....am I correct in assuming that this is a bolt action .22 with a 5 shot magazine?
This was a inexpensive, utilitarian .22 rifle....as were most of the Springfield by J. Stevens line of rifles. I believe it was made in the 1940 to 1948 timeframe.
I'd estimate that the current value would be in the range of:
V.G. - $150
Good - $100
Fair - $70
Poor - $50
P.S. Here's a little info I found on the internet: http://answers.yahoo.com/question/in...7183811AA3UZgn