By low end that is a loaded question. I have a number of rifles with a simple Simmons Pro Diamond 4x32mm. The scope cost under $30.00. In fact on Knight LK 93 rifle of mine sports a Simmons Pro Sport that is a 2.5x20mm and that was $19.95. Now granted they are not top of the line scopes. But they are tough as nails. I would hate to think how many rounds I have put under them and they never lost true zero yet.
But a good low end scope you can not go wrong with is a Nikon Pro Staff (for muzzle loaders) in a 2-7x32mm. Excellent clarity, easy to move powers, very functional, and they don't come better made IMO.
I have a Nikon Pro Staff on a White Rifle that I shoot 460-500 grain conical bullets out of. And it has taken all that punishment and more. Where I hunt shots are close. So if I can shoot out to 100 yards I am all set. Any of them scopes, even the Simmons will do that.