I suppose the question of how to you define ‘Home Defense’ is the central issue? Are you defending your home against a burglar? Ninjas? Government agents coming to take your guns? Zombies?
Let’s assume that you are concerned about a break in and keep your weapon in a sufficiently reasonable, law satisfying container that is tamper and child resistant, what next? Unless you live in a mansion, short range effect is a major consideration. Remember that CCDW tells us that the average gun battle happens at 7 yards (21 feet). Close enough for someone to charge you with a knife and expect to score a hit.
So that takes us to consider the type of ammunition that you plan to use. Do you want a round that puts holes in things and travels on (i.e. 9mm) or are you looking for a round that transfers kinetic energy into the target knocking them down (i.e. .45 ACP or 10mm). While it is fun to put holes in things, is it possible your family could be in the path of the bullet as it travels onward out of your target?
A jacket round is much more likely to in a home defense scenario to penetrate the target. Hollow points, the Home Defense rounds, offer greater kinetic transfer and tissue damage. Frangible rounds that fragment within the body sending jagged splinters in all directions, and may be the origin of the Hungarian word ‘goulash’, settles the dispute quickly.
The experience expectation is high in the burglar scenario that you won’t completely use the first clip (though I would argue that multiple prepared magazines are a wise idea).
So you want a round that meets your expectations, considers your environment, and insures that if you or your loved ones are threatened, you can respond appropriate manner with the correct level of force. Remember that if the burglar is loading your new HD TV into his getaway van, shooting is a poor decision as evidenced by the body of state laws concerning the use of force. So place a high priority on life threatening scenarios where you are justified in pulling the trigger.
Next is the platform that you would use. If you are considering a handgun, what are you comfortable with? Size, fit and feel, the amount of practice you devote to this hobby, your comfort level with recoil all contribute to your accuracy in a life threatening situation.
Likely, your finely made $1500 handgun, that shoots perfectly and accurately, will be confiscated by the authorities when they come to take your statement and cart away your victim / the corpse. So if a $150 platform meets the needs, is it a better investment for your purposes?