I've got an Ithaca 49, mine is a single shot. They did make both a single shot, and a repeater in the 49 model. The value seems to vary widely, I traded some reloading equipment for mine. I've seen them go for almost nothing, and for more than they could possibly be worth, condition doesn't seem to be as big a determining factor, so much as who is buying it, I guess lever collectors would pay more, or any one that had a nostalgia for old lever weapons, my case. $100.00 would be a good starting point for the dickering process. I might even go to $75, and work up from there.
The action is similar to a rolling block in a way, I think they call the action, on the single a "Martini" type action, the top of the receiver drops down to eject the spent round, my rifle doesn't eject LR very well, I haven't tried longs or shorts, yet. It is a lot of fun to shoot, except for the eject problem, I usually have to pull the empty with my Leatherman.
I would probably go for it, especially if it is the repeater model.
You might want to do a little research on gunbroker or some of the other online auction sites.
Doc