Even if you don't wear a suit that often, don't just buy the cheapest one you can find. You might think the $135 clearance price "Chaps" at Kohls looks like a good deal, but it won't fit that well and the pants might split the first time you wear it, much less after a couple times dry cleaning.
Going to Macy's is fine, of the suit lines they carry I personally I prefer Jones New York as a reasonable price/quality compromise. Joseph Abboud is pretty good but I'd probably set a price target of $400 on one. Hugo Boss is fine but tends to be "slim" cut and I prefer a bit more room. I bought a Calvin Klein suit and although it's not terrible, I'm not going to buy another one either. I'd avoid altogether the following brands: Alfani, Ralph Lauren (or their Lauren line), and Perry Ellis. It might be worth taking peek in Nordstroms to see if you can get lucky and score a Hickey Freeman clearanced down to your price target, if so you'll have a great suit that will do you proud and will last near forever.