I agree.. first look at your wallet and see how fat it is and how skinny your willing to make it. Then look at your hunting situation. Where I hunt 50 yards is a long shot. A simple 4x even 2x work fine for me. But out west where some hunters are shooting 200 yards and further, then a good 9x would be the ticket.
I always felt for a muzzleloader a 2-7x32mm was about the perfect scope. Let me qualify that statement. I do not shoot 200 yards not would I probably ever try. I have target practiced out to 150 yards and that was with a simple 4.5x32mm scope. Once I learned the drop and the placement of the cross hairs, the rest was easy. But where I hunt, 2x walking through the woods is perfect. On an open stand I will crank it to 5x even 7x in a hay field. But again, 50 yards is usually my max. So a 2-7x32 fits my needs perfect. They gather more light at the end of the day then a 3-9x40 most times, have a smaller bell so I can mount them closer to the barrel. Are often less cost wise.
One of my favorite scopes is the 2-7x32mm Nikon Pro Staff. Just a good solid scope, well made, great glass, great warranty, and they don't break the bank. I have then on four of my rifles. I also like the Nikon Omega 3-9x40. Or the Bushnell Elite.
Lately I have been seeing if I can destroy a 3-9x40 Cabela's Powder Horn. I broke one and have one to go. But again, a very good scope. It just did not stand up to the abuse I put it through.
So think of what you want the scope to do. And what kind of shooting you are going to encounter. Then look in your wallet and see how much you want to invest. I have a number of rifles with a simple 4x32mm Simmons Pro Diamond Scope. And that is an easy 100 yards scope. Cost wise, if they break... I throw them away. Although Simmons will replace them. And the glass in them is exceptional for the cost of the scope ( $39.99).