@lutorm and @Villanelle, you have it wrong in the FIRE calculation. My FIRE amount is the amount I need to live including these £2k extra.
So at £1.5M at 4% I should have enough to spend these £2k extra + my current normal life. Of course, it should still work if an unexpected crash happens and long bear market, for which I'd obviously spend less like everyone.
So no I won't feel more deprived once I FIRE and I can either spend a bit more now and take longer to be there or not.
@Malcat I'm also interested on people position toward that. It seems that most people want to be FIRE asap. But I'm now thinking maybe it's not the best approach? Although it depends on case by case. You can see on the survey 1/3 are happy to take the long road instead!
@wageslave23 it does bother me quite a lot actually. Sometimes I just want to quit and forget about it. Recently I was even considering doing VERY LEAN fire and quit on £650k.... but then some reasons came back to mind and I'm back to work. Need to have at least a bit more. Maybe I'm looking for reason to be happy while getting a better stash... because it's a VERY LONG road!
In that case, if you spend 2k less, you need less money to FIRE. So either way, your time math is wrong because you are working to get to the same FIRE number in both scenarios. You need less money to spend X-2000 per month than you do to spend X per month. I'm not sure how else to say that so you understand it, so here's some numbers.
In one scenarios, Bob spends $60k per year. He needs $1.5m to fund that (at a 4% WR). In another scenario, Bob spends $2k less per month (before and after retirement), or $24k less per year so he needs only $900,000 per year to FIRE. But both of your scenarios have ~$1.5m as the bottom line, when in reality, in the first scenario you are not adding to your stache more quickly, but you get to stop at a smaller number. You haven't accounted for that.
If you are saying that no matter how much you spend now, you need 60k/yr to spend in FIRE, that doesn't make much sense. Are you saying that you would be able to not spend that extra 2k now, but once you quit it will become necessary? Does that make any sense?
In the end, it's your money. Do what makes you happy. But as your numbers stand now, you aren't looking at the actual cost in years worked that you will pay for this inflated lifestyle.
it also seems to me like there is a lot of territory between 0 and 2000. For me, the right answer would probably be found somewhere in that territory. £2000 a month is a LOOOOOOT of money. It's more than some people live on. Buying an extra 200 or 500 of extravagance per month allows you to attend several fancy dinners with friends and a couple cocktail hours as well. How on earth do you need £2000 every month, in addition to your current budget which I suspect has a fair amount of fat in it, to do that?
It seems like you are making excuses not to sacrifice much of anything or to ever have to say no to a single invite, or to ever only have 1 cocktail. You've made this a binary thing--no additional money or sooooo much additional money--so that you can tell yourself that no additional money feels too constrained and affects your happiness, so I guess that multiple £200 dinners and £25 cocktails each month is the way to go. And fine, if that's how you want to live, vaya con dios, friend. But it's ridiculously wasteful of both your time and your money, and I think you know that on some level or you wouldn't be here asking this.