Tenn870,
The most common ones are the Egyptian contract 8mm. They must have purchased several hundred thousand in their day. I know there are figures somewhere on the internet, just don't keep that detailed stuff in my head. You have to watch bores, since so much 8mm is corrosive. Many of the FN 49 8mm have pitted and dark bores. You can sometimes find a Century "put together", which means, Century also purchased a large store of spares, and had these assembled with reproduction Italian stocks. The easiest way to tell them is the butt pad is a black plastic with absolutely no checkering of any sort. These are fine shooters., not so much collectible, but who knows!? Maybe one day. Here is an example of one.
http://www.gunbroker.com/Auction/ViewItem.aspx?Item=190138363 . Price range for 8mm, depending on bore, and a few other things is $500 to $850. You really need to see the bore or inquire if shopping on line. Many times, they will not mention the bore condition and it benifits you to ask them for all the detail they can give.
There were a couple of countries that bought them in 30.06, but that number pales in comparison to the 8mm. I think Belgium and Luxemberg both bought the 30.06. The 30.06 will cost you a bit more, with many of those topping a grand. You will probably find more of these with really clean bores. Mostly because even if the contract countries were using corrosive ammo, I would assume they had better trained and equipped troopers. That means the rifle got better attention over what an Egyptian conscript soldier would probably provide in arms care. Prices on these range between $800 to $1,400.
And finally, there are the Venezuela 7mm versions. I personally love the 7mm, but it is the hardest to come by as far as surplus ammo now. I had one back in the late 80s and you could still get surplus 7mm. Sold that rifle years ago and always wished I hadn't. Most have muzzle breaks and the 7mm is a low recoiling round, especially compared to the 8mm and 30.06. A very nice rifle, but you have to be prepared to pay a premium for the gun, and then hunt around for the ammo. Prices usually are between $800 and $1,200 on those. They have a bit of a "collectors" premium on them. Doesn't sound like the right one for you?
Just a note: Beware of the so called "Sniper" versions. I have seen the surplus and aftermarket scope mounts and scopes ( I recall when they came up for sale about a decade ago) placed on standard issue FN49s and then presented as "sniper rifles". Seems to me I read before that FN didn't produce a sniper version, but that could be wrong. Just suffice it to say, you aren't looking for that type of collectible from what I gather, and would be better off not to attempt to get into that end of the FN 49 market. I know the Mas 49/56 has the same situation. It was too easy to buy a surplus scope a few years back, marry it to a standard rifle and then viola! A sniper rifle for 2 to 3 times the normal price.
Btw, the accuracy is excellent on all these rifles. Of course, bore condition will have an effect.
All the best.
