My rule of thumb is that you have to pay me an extra $20,000/year to have me show up in a suit. At some point I'll bother increasing that differential.
I'm employed and am facing no offer that would make me consider wearing a suit. However if I was unemployed, I'd wear a suit in an instant. And smile. Behind gritted teeth.
I'd also get a better job as soon as I could...
Cheers,
Ben