Get the best you can afford. Same rule for scopes. I have a 7 year old Leupold RX3. Longest animal I've ranged was a white goat at 1107m in the evening, but typically the range finder is good to around 750m on a deer. Which is further than what I'd shoot. When I upgrade, I'll get a Leica 1600.
If you wan't to try before you buy you could always set a few markers down the road of your LGS and take one outside, see how far it really works vs what the box says.
Savage 14/114 American Classic 30-06 Springfield Savage Axis 25-06 Remington
I ended up getting a Bushnell "The Truth" odd name for a range finder but it works OK. They guarantee it to range an animal at 200yards but I ranged a cow down in the paddock at just over 300. It's not top of the line but you can't have everything. JD
If it's not wood and blued steel, it's not one of mine
That wouldn't fit on the side of the unit mate, that's one reason. However you can spend a small fortune on things like this, but really, who cares if you can range animal at 1500m or more. A sensible hunter will seldom shoot at a range greater than 300m anyway. JD
If it's not wood and blued steel, it's not one of mine