Vortex & Sig Sauer’s line of Low Power Variable Riflescopes compared to more expensive models

Hi,
I have been buying scopes for every rifle I have purchased and a few are Vortex, Sig Sauer (i.e. 1-4, 1-6, 1-8, 1-10…etc) because of the cost compared to their own higher end LPVRs and other high end brands that their costs starts in mid $1,500 and higher. What is the difference between the ones that cost less than a $1000 to the models that cost over $1000? Are you getting more for your money? Are you getting better glass? I mean can you tell the difference if you do a side by side comparison? I have purchased a couple of Steiner’s. I read that Sig Sauer and their lineup has won government contracts for the past three years. Bottom line is if I don’t have to spend over $1000 for something that is just as good under $1000 then spend it wisely. Thanks in advance for your inputs.