my 2 cents:
shop for high quality but recently discontinued leather one pc. suits after first having tried them on carefully, with knowledgeable dealer assistance to verify correct fit. one pc. suits MUST fit you properly, so be patient until you find exactly the right fit. then save by being patient enough to wait for the sales on discontinued models.
I got my Alpinestar suit that way and am totally pleased. Also note, if not used to one pc. leather suits, give it time to get used to it. Typically, it will stretch and mold to you a bit after just a little hot weather riding, especially on-track where your sweat will help break it in. In that regard, look for a high enough quality suit, that it has, among other things, a good liner, preferably removable. After that, features to look for are high quality construction, which you can still get even in the entry level models of the better suit lines, and then good armor, vent or perf. design, room for back protector, etc.
See,
www.webbikeworld.com for reviews along with detailed info on how to buy a suit.
For track day people who are not racers, a good brand, entry level suit should be fine-- most popular seem to be Alpinestars because they seem to fit more people better most of the time, followed by Joe Rocket, followed by many other good brands. See also,
www.newenough.com for excellent deals and information on suit fit and buying.
One last note-- finding a suit that meets the criteria I've laid out will probably put you at or a little above the $500 mark, unless you happen to find an extraordinary deal. So be realistic about the market, unless you want to try going with a used suit, which will raise other issues beyond the scope of my comments.