There's only one thing missing from this conversation; I'm assuming that the OP and probably everyone responding to this thread has MUCH "younger" ears than I do, and almost certainly much better hearing; I'm a text book case of what happens to ones hearing over a life time, when you take a lacksadasical approach to protecting your hearing; trust me.....after it's gone, it's gone for good! Regardless of you age now, firing ANY large caliber handgun in a confined space, (such as inside of the average home ) without serious hearing protection is a sure-fire recipe for ruining your hearing and needing hearing aides much sooner than you probably would otherwise.
Obviously, if you thought there was much chance of a burglar or "home invader" breaking into your home wearing body armor, then I'd say probably have a S&W .500 magnum with 10 inch barrel handy; but being realistic, I'm guessing that the chances of that happening are very slight.
As far as the 9 mm round being a "small, light round".......yeah, compared to the many much bigger thing out there, I suppose it is; personally, I'm of the opinion that if you can't stop a home invader with a 17 round mag full off 9mm, you probably better forget pistols altogether and have a good 12 gauge shot gun handy.
Another thing to consider......where is YOUR house located, relative to other houses and people? There's a LOT of energy behind ANY 45 caliber round; (have you heard the horror stories about people shooting a burglar in their house and "taking out" the guy next door in his kitchen? ) Going to the other extreme........and please don't ask me how I know this, but I do; for many years, (and I'm guessing still today ), the Israeli Mossad had / have teams of people whose sole job was / is to "eliminate" certain individuals; and the standard weapon used was ALWAYS the same; MANY enemies of Israel have been found deceased in doorways with seven .22lr rounds in their brain and chest. (almost always fired from less than three feet away. ) I can tell you that all of these people are highly trained and VERY accurate as to "shot placement".
I'm also hearing lately that quite a few PD's are trading in their G 22's and 23's and going back to the G 17's and 19's using the 9mm round. (Lotta reasons behind this )
Finally.....if you think having to "shell out" 2k for a great custom 1911 is "painful"........wait til you're obliged to come up with 4k to have a tiny little digital, electronic "gadget" sitting on each of your ears so you can hear when your wife is yelling at you! (You'll become much more mindful of protecting yourself from loud noises. )