Well...mine was really only fueled by theft. My original set was stolen and after hemming and hawwing a few weeks about whether or not to really replace it, despite my initial desire to do so, we did decide that if I didn't I would regret it and we would never save enough to replace it when we spent that money.
I wanted exactly what I had before, as far as the stone was concerned, however I was met with supply issues. This brand of cut is not as widely available as it was when we were initially looking when we got engaged. We also wanted sometihng with a better clarity grade after realizing that we were never going to get lucky like the first time, where there were no inclusions that were visible with a 10x loupe with one exception, that was prongable (though I liked it so we didn't cover it). Because the company no longer bought or cut rough that was higher than SI1 clarity, we had to sift through available stock and trade-ins. At first I was frustrated with that, but it became more worth it. Because of that, we were limited to specific size ranges. So our size increase was mostly out of that. Not that I was complaining. HAH! I had to either settle on size or clarity, or get a different type of cut, and I was just not in love with the "regular" hearts and arrows round, despite my budget allowing a much more sizeable stone than I ended up with. It felt unfinished since I was used to more than 2x the standard facets.
We ended up putting out more money than the initial insurance payout to get this stone because we were both so happy with it, though for a while I wasn't 100% in love with it because it wasn't the same, and it was also VASTLY more expensive. But over time I grew to love it. I also made sure I was never "stuck" with the stone, as I bought it from a jeweler with a killer return/upgrade/exchange policy. So if I ever win the lotto and choose to trade this in, I have it made, OR if I get sick of it, I can always exchange it back for another.
But my increase was NOT dramatic at all. I went from a .86 to a 1.15 which gained me about 1mm in Diameter. AT first it was ridiculous and I was regretting that, but now I am totally used to it lol....I could go bigger at any time. HAH!
I get snide comments just as frequently as I get really really amazing compliments. I just accept that negative comments are because it's not to someone's taste or they are simply jealous of my good fortune. I kind of laugh when people get all "well it's nice that your husband is rich and spends lots of money on you, he must love you". Or even "you guys make enough money, why didn't you hold out for bigger. He must not value you that much." First off, money spent has nothing to do with the amount of love he has for me. We could have even afforded more than we spent, we just are both more reasonable about our frivolity and didn't feel more was worth the spend. He does no jewelry shopping or buying without my 100% involvement, because I love it, and he knows I am knowledgeable and have particular tastes, and he doesn't feel jewelry is something you "surprise" someone with, as it's personal. But money isn't the deciding factor of love and life which seems to be where the majority of the comments we get come from. We realize this is in no way a necessity of life. It's a luxury. We both work hard, we both earned the ability to spend our money as we see fit. So I don't feel like I need to answer to people like that.
I also get a lot of flack from friends and family about it. We have had some unfortunate luck/experience in the custom jewelry department. So I am definitely concerned about backlash from that. The amount I have spent in redos after poor workmanship issues...staggering.