We get a chance to look through a wide range of very spotting scopes at F class matches - scoring and general glassing.
Unfortunately, 'ED' on the side of the box may not mean a whole lot. I have seen some non ED spotters that were sig better then so called ED ones.
Boils to what actually made it into the spotter.
If the idea is seeing holes in the target at 300m, I really doubt ANY spotter will let you do this in the black when the summer mirage is up.
In the white, a wide range can work depending on ambient conditions. In good air, all the better ones can see 6mm holes in the white at 500m.
This is a cope out of sorts but it really is important for you to look through the spotters to see what works for your eyes. There are alot of mega dollar spotter that don't work for me and my glasses.
If you wear eye glasses you need at least 17mm of eye relief at the power setting you want to use. 20mm is very comfy.
for the budget you are thinking, go good quality used like a bushnell Elite which is supposed to have a form of ED glass.
Although their binos are great, Nikon spotters are not to my liking.
Pentax 65 and 80ED spotters are superb but the eyepiece is worth more then your budget. The variables that come with these are not bad but no where near as good as the fixed mag ones.
Then you go to KOWA/HOWA, Minox and on and on.
I am presently using a Celestron 80 spotter. Decided to not go for the ED variant to save some dollars. Very well priced in this group. Decently constructed and decent optics in the lower mag range. Eye piece has very nice eye relief (why I bought it) at lower mag.
I am using this for condition reading and some light work spotting. The glass simply cannot compare with the big dollar spotters but it very decent given the investment.
try and get out to a F class match and you will get to see a wide range of kit.
About the only way to know for sure where to spend your $$$
Jerry