I buy most of my clothing on eBay and in consignment shops... second hand, for the most part, though quite a bit new.  And my sense of perspective is a little skewed, I'll spend insane amounts on a costume that I'll only wear once or twice, but skimp on underwear I wear every day.  But to give you a rundown:
Suits: I don't own a suit that cost more than $300, not even for costumes.  I will buy three-piece suits just to get the vest, though I do sometimes wear the pants too, and will generally spend $80 to $150 on eBay.
Pants: aside from the pants that come with suits, I only wear khakis, and I get them at Old Navy and Kohl's for the most part, anywhere from $15 to $30.  I have two pairs of jeans, one Chaps and one Lucky Brand, that I bought in consignment shops for less than $20.
Shirts: I seldom pay more than $35 for a french-cuffed dress shirt, and usually pay around $20.  I won't pay more than $25 for a barrel-cuffed shirt, and if I shell out more than ten bucks for a tee-shirt or thermal, it had better say something utterly hysterical on it.  Dress shirts mostly come from eBay though I find at Ross and Marshall's as well; tees and thermals mostly come from Gap, Old Navy, and Kohl's.
Sweaters: my weakness, I have so many of them I don't know where to put them all.  But again, I like quantity, so I don't spend much per piece.  Consignment stores are my favorite venue for them, though eBay, Gap, Old Navy, Ross and Marshall's are also frequent contributors to the collection.  And I don't believe I've ever paid more than $50 for a sweater.
Vests: another weakness... I wouldn't spend more than $30 on a sweater-vest, but I will spend well over a hundred for a custom-made waistcoat, and as I said before I'll sometimes buy whole suits just for the vest.  
Shoes: I think the most expensive shoes I own are the Dr. Marten's I paid $75 for on sale.  No, wait, I own a pair of riding boots for which I paid $250, and I've only worn them three times, always for costumes.  But in general I pay around $50 for a pair of shoes.
Underwear: I get 2(x)ist boxer briefs at Marshall's for $5.99 a pair, or Old Navy boxer-briefs for $10 a pack of three.  I recently got some Hanes that were on a good sale.  I'm not all that picky about my underwear, nobody but me ever sees it.
Socks: I usually wear white gym socks with sneakers, $9.99 for a pack of 6.  I also have a lot of kilt-socks, and boot-socks, and argyle socks, and like that... generally around $5 a pair.
Accessories: this is where I go a little nuts... hats are expensive, and I wear hats every day.  But the most I've ever spent on one hat was $95, and that was on impulse.  I'll usually spend anywhere from $50 to $75.  Ties and all that sort of thing, I tend to get at consignment shops, vintage shops, and of course eBay.  I think $10 is more than enough for any kind of tie or handkerchief or scarf.
So I think the theme is that I don't like to spend a lot on any one piece, because I like to have lots and lots of pieces.  Since I have so many pieces, I don't wear any one piece all that often, so the quality of wear is less important than fit and color.  But I still prefer to benefit from other people's spending practices and buy their old and barely-used high-quality stuff on eBay and at consignment stores.  I have a Calvin Klein cashmere sweater that I paid $5 for at Out of the Closet... if you're willing to do a bit of trolling about in shops and online, you can find bargains like that.  
I think the main point of paying retail is the convenience.  You can go into a department store and shell out a thousand bucks for some good basic outfits in one spot, where I'd prefer to spread that over three months and two dozen shops, and get a whole pile of clothes.