everyone has different valuations on the things they are interested in. most of my friends give me crap for talking about spending a few hundred on earphones, but then again you have the masses who spend hundreds and thousands every year upgrading their mobile phone or whatever hobby they have an see no issue with it (generalisation).
but essentially, most of my friends bar a couple here and there, think that my expenditure on audio equipment is unnecessary and more often than not give me the shits for it even though I haven't even spent more than 2k on it.
at the end of the day, I know to myself that we all have our different likes and dislikes and we will always have hobbies. I always tell my friends that the gap between a low end earphone and mid-priced earphone is pretty big, but once you get to the upper echelons, it's diminishing returns that comes into play and it just becomes how much are you willing to pay for that little extra.
it's like a vice at the end of the day and as long as we don't start thinking that our hobby/audiophile equipment becomes more important than life and friends, then we are all still sane :)