Somewhere I have a book of ‘cowboy with and wisdom’. One bit of advice is ‘Never ask a man the size of his spread.’ If you have 100,000 acres and enough cattle to populate a medium-sized city and the other guy has 40 acres and a mule, you’re likely to make the person uncomfortable, envious, or resentful. If it’s the other way round, then the other guy is bragging. He has enough that it shouldn’t matter what other people have. It’s like asking someone how much they have in their bank account. It’s just rude.
I’ll help someone out who is legitimately looking for advice. I didn’t mind saying how much I paid for my new refrigerator when someone here was looking for a new fridge. Questions about other things, I find intrusive. Though I started a thread on this very subject a few years ago, I haven’t spent a lot of time thinking about what I will and won’t disclose. I think that for me it comes down to luxury items. I won’t say how much I paid for a couple of my watches. Nobody asks, but if they did I’d tell them to google it. If you want Luxury Item X, you probably already have an idea of how much they cost. If you don’t, then you don’t have Need To Know and are just being nosy. It depends on the context. Is the person just curious? Or is he being nosy about my finances? Is my answer going to provide useful information? Or will it evoke envy, or will the person think I’m an idiot for spending money on such a thing? In the end, it’s rude to put a person into a situation where he or she must consider the context.
I think it was Mark Twain who, when asked his age, said ‘As old as my tongue, and not quite as old as my teeth.’ A similar answer might be used for costs. I’ve told people ‘Two dollars and eighty-five cents!’ and ‘A miiiiiiiiilion dollars!’ In answer to some questions I’ve found intrusive, I’ve said ‘Why do you have a need to know?’ If pressed, I say ‘Seriously. I’d rather not say.’ The questioner might just be making conversation and see nothing wrong with asking. But if an answer might establish some sort of status or make one or the other party uncomfortable, it shouldn’t be asked.
ASIDE: I was attending a little party on a VC-10K tanker. A woman kept asking of the plane, ‘How much does this cost?’ What, she’s going to buy one?