Never understand why people think we "must be rich" to afford $350 to $699 watch, yet someone next to me wearing a $30,000 Rolex is not considered rich. Or who spend $5 a day on Starbucks ($1,825 a year on coffee).
Personally I find it very rude to ask how much people spent on something they're wearing. IMO it falls under the same category as asking what their income is. Show some respect.
I genuinely thought that was an acceptable question in the US. I've been at some very awkward dinners where American visitors have grilled a group of mortified English people about their incomes. A total no no in the UK.
The cost thing annoys me too. If I was off on a £5,000 holiday no one would bat an eyelid, but a £599 watch is seen as verging on immoral.