Yet another submarine: http://paulgraham.com/submarine.html The suit is dead for any number of reason, dittos bespoke clothing. $4000 is several times what I spend on clothes in a year. It's several times what I spend on clothes in several years. There's a far less expensive option that's highly satisficing. Suits, once an inexpensive, practical, standardized alternative to more ornate and expensive clothing, are now…
Why do you think the suit is dead?
I wear a suit (not always, but often enough to have an opinion).
I've never bought an expensive suit, but I nor do I buy cheap suits. I guess I generally spend around $500.
I work with people who spend $2000 on suits though. These aren't bespoke, but are from nice fabrics and cut very well (eg, Hugo Boss etc). I'm no suit expert, but I can tell the difference.
I can't say I've seen any particular decrease in suit wearing over the past 15 years I've been working, although ties are less common that they used to be.
In my experience location and field of work makes a bigger difference to suit wearing than anything else.