Good suggestions by the guys above.
One scope I have a lot of respect for, and in your price range, is the Weaver V-16.
I've owned a total of seven of them over the years(not all at one time), and now own three. The have some advantages other equally priced scopes don't have, like focusing close (10 Meters IIRC), have an A/O focus, are tougher than nails, and have as good a glass as any in the price range.
I began using them 10 years ago for air rifles, as all of the guys shooting air rifles recommended them. They are able to withstand the violent forward recoil of springer arir rifle like the R-1, and the RWS heavy recoiling rifles.
I'ver never had the opportunity to compare them with other similarly priced scopes like the Mueller, so I can't say one scope it better than another. The only thing I can say is I like the V-16, and will always have at least one on a rifle.
I also used the V-16 for rimfire rifles as they are easily adjusted to shoot short ranges.