I would go with a nikon monarch for what you are looking for maybe stretch out your cash for a bushnell elite 4200. The 3-12x42? maybe 44 in the nikon is around 300 and is a lot better optics than the leupold. Leupold is not very good on price point but has the best customer service. Also google some articles on optics here are some basics sorry if I explain the obvious, not trying to insult.
A scope 3-12x42
3-12 is the power range 3x magnification to 12x
42mm is the objective lens diameter it is the end of the scope that receives light the ocular is the end that you look through
this measurement of the objective is often a source of debate, people think bigger objective equals a brighter scope, not quite, the objective I like to explain as the quantity of light that is allowed in, not the quality of light. The objective does determine your exit pupil
exit pupil equals the magnification setting the scope is on divided into the objective, for our scope on it highest setting the equation would be 42/12= 3.5 mm
So what is the exit pupil it is the diameter of the light that is broadcast from the ocular lens to your eye. The human eye cannot dilate to more than 6mm normally so your exit pupil only need be about 5mm getting below 4mm things will appear darker and not as sharp in lower light condition so in low light our scope would do well to be at 10 power or less. In broad daylight you would not notice. So will a scope with an exit pupil of 10mm look brighter in low light than one with a 6mm exit pupil, no because your eye only goes to 6mm, the extra will amount to nothing.
So then what determines how bright a scope is? Light transmission well if both scopes have adequate exit pupils it will come down to quality of glass and coating expressed in light transmission. However the only people who really test this and publish it are the optics companies and they will lie. Leupold claims that they have scopes with 98% light transmission. This is not possible. One piece of glass can have that rating but after passing through other lens and prisms it will lose more light until it is probably down to the high 80's like 88% percent light transmission. So to see how good the glass is go to a cabela's at sunset and ask the scope guy on a quiet night to go outside with a couple of your first choices and see what you can see. They will let you. I used to do it for customers all the time. I like the Nikon, bushnell elites, burris, and weaver all make excellent glass.