Dunno if a Simmons 44 Mag's objective lens is too big, or not. I got mine for $100 from Cheaper Than Dirt.
Burris, Simmons, and the Tasco--but not the bottom-end Tasco. Check out WallyWorld prices, and look in Shotgun News and your local stores.
Used scopes at gunshows can be reasonable deals, if you know your WalMart pricing and can argue.
Just stay away from these strange-name or no-name el cheapos.
A test of a variable scope is to shoot one shot at maximum magnification, followed by one shot at minimum. If they're closer together than your normal smallest groups, you're in Fat City. A practical note is that when you're using the minimum magnification the target is fairly close. If your scope is not all that good, the spread won't matter because of the lesser distance.
FWIW, Art