I think that someone like you should figure out how to implement "conspicuous charity" - figure out a socially acceptable way for people to compete on displays of wealth and taste based on what charities they give to, and how much they give.
As an aside, I think it's your money, and if you want to spend more than I would spend on a server (which is to say, way more than I'd consider spending on a car) on a fancy watch, well, I'm going to make fun of you a little bit, but ultimately, it's your money, and your judgement. But, if fancy watches are primarily signaling, which I believe to be the case, it seems to me that you could figure out how to get the same signaling value out of proving that you gave a certain amount to certain stylish charities.
High end brands could release limited edition colors of their products at a higher price with the additional money going to some efficient charitable organization. Who wouldn't want to have an EFF themed Tesla to show off?
As an aside, I think it's your money, and if you want to spend more than I would spend on a server (which is to say, way more than I'd consider spending on a car) on a fancy watch, well, I'm going to make fun of you a little bit, but ultimately, it's your money, and your judgement. But, if fancy watches are primarily signaling, which I believe to be the case, it seems to me that you could figure out how to get the same signaling value out of proving that you gave a certain amount to certain stylish charities.