any suit that retails less than a thousand is a piece of ****. the lapels don't roll, they are structured with glued fabric, they don't fit well and they look cheap. look up online the difference between a good suit and a bad one, and you'll never go back. i have an $700 calvin klein suit, that is made like a cheap suit and if it weren't for the cut would be nothing but trash. I got it on sale though for a party, otherwise forget it.
either go cheap or all out. a 500 dollar chaps suit is no better than a 200 buck perry ellis one from mens warehouse.
if you buy polyester, no one can tell until you're close up, but it just feels like crap. if you like sweaty balls, by all means indulge. sometimes newer fabrics have a little poly in them for effects, like streching or shinyness, thats ok becuase those are more stylized pieces.
i suggest finding something good on ebay and tailoring it if you can't just get it from the store. saks outlet usually has nice ones for 500 bucks. i dunno, brooks brothers is good priced and their suits look ok. anything tailored is good, because they can't cut too many corners. don't buy a straight black one so you can wear it elsewhere, since its probably safe to assume you don't have any other suits.
i know a lot of about suits and clothes, so please don't brush off what i'm saying. try on a canali/cornelliani/brioni/hickeyfreeman/armani/zegna and compare it to anything at macy's or men's warehouse and tell me you don't feel different. a decent tailor usually can make a nice suit for less than a thousand, but thats if you stay away from super 140's and special kinds of wool. clothes shouldn't make you more confident and look better, but they do, so if you wanna shine, try it out.