This is a quick summary from memory and probably needs some supplementation and correction, but for what it's worth...there are several periods for 94s.
I think the gold standard for 1894s is pre-WW2. During the 50s, Winchester was already under pressures of inefficient production methods and they are not necessarily great guns. It is kind of like the BP era for S&W: many of the guns are great, but there are some lemons out there -- more than should be.
It was those cost and production issues that led to the 1964 changes. Those 94s have things like stamped lifters and if you're looking for a good example just to have one (a very valid reason), I'd avoid these like the plague.
Sometime around 1971 or so (could be a couple of years off either way, no books here), Winchester woke up and put some of the quality back into the rifles. I've owned two of those. One came out of the box with the front sight soldered on with a roughly 10 degree list. Ahem??? I still have its replacement. It's a functional and durable rifle. One thing -- the receivers are (IIRC) malleable iron or the like with a plating that allows the surface to be blued. If you wear that plating, you will not be able to reblue (like on mine). Good users, ok as an example of a 94 but not the best.
Later -- and I forget the years -- you get cross-bolt safeties and AE models -- these are really too far away from the classic JMB design for your purpose (at least that's my guess), so again, you probably want to avoid.
Short version -- pre-'64 is OK, but you may want to look for a pre-war version in good working order. That would be my take on it -- YMMV.
On price -- shop around. There are more than a million of these out there and prices vary a lot in my experience. If you're patient, you'll find a good example and a good value. Check the Blue Book-type publications for a start. Check with local stores, especially in the winter and spring when hunters are trading rifles, thinking about next season. Go to gun shows and make offers. (You may want to print out a list of serial numbers by year so you can get a grip on how old the rifles you're looking at are.)
BTW, if you're looking mostly for a good example of a classic rather than a rifle to take into the field a lot, you might consider expanding your search to include the .32 Winchester. They represent a big percentage of 1894s and generally sell for less because the .30-30 is so synonymous with the 1894. For your purposes, maybe it doesn't matter? There was a great article on the .32 Winchester in a recent issue of The Accurate Rifle.