Bushnell Trophy TRS-25 1xRed Dot Sight Riflescope
That is about $80.
It is less than 4 ounces.
I have not beat it up, but it seems to work perfectly.
For a hunting gun, I can't see anything wrong with it.
Maybe for troops in military situations they need something heavier duty, but for mounting on a gun that is going to be mounted on a gun that rides in the car in a hard case, and then get carried around carefully once a year, this should do it.
Here is a pretty good video about it