I shoot Sniper Matches with targets from 100 yards to a maximum of 800 yards on my home range. We also shoot a match we call a Multi Range F Class. We shoot 5 rounds from each shooting berm starting at 100 yards and moving back to 800 yards. Fourty rounds total.
I have two MK IV M1 16X Leupold's with TMR reticle's. I have a 6.5 - 20X M1 with Premier Reticle Gen II Mil Dots. I also have a 8.5 - 25X M1 with Premier Reticle Gen II Mil Dots. I also have 4 Super Snipers in either 16X or 20X.
Shooting to only 600 yards any of the above will work fine. They are all 30mm scopes.
Do not buy junk. A good rule of thumb if it is not made in America, Germany or Japan, it is probably junk. If it is made in China it is almost surely junk.
Super Snipers are around $300 last I checked. They are made in Japan. They are good to go for an econo fixed power 16X or 20X scope. The glass is pretty good, but not Great. Knobs are not bad with big lock screws, and they dial accurately. The rear focus works just fine. As far as I am concerned the next step up from a Super Sniper is a Leupold at triple the cost. In a Leupold get a 30mm tube, and M1 Knobs. The Milling reticles are nice, but 80% of the folks I have seen who own one have no idea how to range targets using mil's. They probably have no need to know either, for that matter. If you find a cheaper Duplex it will work fine. As for power, mine stay turned up all the way for range use, unless we have a target that is almost under foot.
In my opinion after Leupold and Night Force you are paying way to much for very small gains in quality. Just my opinion.