I've never spent more than $400 on a scope of any kind. I never saw the need for it. I've bought Sightron, Clearidge, Bushnell Elites, Leupold and Burris. I've only had to return one Burris for repair. That was a 6X HBR target scope that I could not get the parallax out at 50 yds. It was fixed and returned. I competed in rimfire benchrest and had $3,500 custom rifles which had Sightron II 36X and Burris HBR 6X scopes, which cost then in the $200-$350 range. I competed very successfully against shooters shooting Nightforce, March and the Leupold Competition scopes. I wasn't so much concerned about optical perfection. All I needed to do was to be able to see the target and be able to resolve the scoring rings. What I was concerned about was the accuracy and ease of use of the adjustments. When I wanted to make a 1/16" correction (50 yds), I wanted the one click on the adjustments to give me that. My Sightron and Burris scoped did just that. I achieved Gold level status in the IR50/50 Hall of Fame, won the 2015 Unlimited Nationals and made the US team that competed in the 2011 World Championships using these scopes. I used them for over 10 years and never felt the need to change and never felt I was at any disadvantage. I wasn't out there bird watching, all I needed was to see the black rings on a white paper and a scope that could make and keep very minor but accurate adjustments, when needed. These scopes did just that.
As for hunting; I live in the NE and big game is typically shot at less than 100 yds. most under 50 yds. I don't need a $1,000 high magnification scope to do that. My 2-7 and 3-9 or 3x fixed scopes from Leupold, Bushnell (B&L) and Burris have been able to allow me to see and kill many a whitetail and none have failed, needed repair, or replacement. If people want to count the feathers on a chickadee while deer hunting, then yes I can understand spending thousands on a scope. Or if your type of hunting requires a high magnification range and ultra resolution then maybe. But, I see no sense to any rule of thumb that you should (or need to) spend more on your optics than on a rifle. If all you need to do is put the crosshairs behind a buck's shoulder and have the shot go there, then a $200-300 scope is more than capable of doing that regardless of what you paid for the rifle.
