For home defense, the shotgun is definitely the ultimate. And the good thing about a shotgun, is that they don't really wear out. People don't usually put thousands upon thousands of rounds through their pump shotguns. As such, while you can indeed get a maverick for $170, you can also walk into most gun shops and pawn shops and buy a remington 870 or winchester for around $200. And personally, I would take a used remington 870 over a new maverick, if the price was close to being the same.
If you want to go with a pistol, the same rules apply. If you're only going to use it for home defense, you should look at a 357 magnum revolver. It doesn't matter if you are 4 foot tall and 90lbs, or 6 foot tall and 300lbs. You can find a load of ammunition to fit you. As light a load as a 380 or as heavy as a 41 magnum. Don't let people scare you into believing that you're going to get into a "Gunfight". Especially in your home. You don't need a semi-auto with 15-18 rounds in it. If that was the case, then a shotgun wouldn't be a good choice. And I don't know of anyone who would say that a 12 gauge shotgun isn't probably the best home defense weapon available.
If you're looking for a gun that you can also double up for carrying in public also, then the 357 magnum is still a great choice; but depending on what your needs are, there might be some semi-autos that would be better. And of course, if you can or will be having more than one gun, then you can specialize on different guns. Some are perfect for self defense (Out of the house), while they suck for home defense. Likewise, there are some that are perfect for home defense, but suck as a carry weapon. So, you could have both. Both that's something you have to decide. The hardest choice is when you're only going to have 1 gun, and want it to fulfill numerous purposes.
P.S. That $169 price for the maverick would NOT be the final price for you. That gun comes with a 28" barrel. That's almost IMPOSSIBLE to swing around in your home for defensive purposes. If you're looking for ONLY home defense, you want to find an 18" barrel if you can. The 28" will bang into walls and all sorts of things while you're moving about. Great for geese, sucks in the house.