You sound as if this will be your first bow. If so do not order one from any mail order company until you really know what you are looking at and what all goes into setting them up. Go to a pro shop so that they can fit the bow that you want to you and you can try as many as you can before puting doun your hard earned money. There are a lot of differances between bows like grip designs, how smooth, harsh or soft a draw cycle is, how short or long the let off valley is, how heavy the bow itself is, how it balances in your hand, etc...etc...
After saying all of thet, do you want the bow itself to cost under $400 or the entire package under $400. either way, IMHO, the best package out there that's in this price range is the Parker stealth hunter outfitter and the hunter mag outfitter. These bows are smooth drawing, have a generous valley, good brace height, good wall to draw against, excelent build quality, and great speed.
I don't know of any other bows out there for this price range that are going to give you as much for your money as these two. Heck, with the outfitter deals you even get a hard plastic case for storage and transportation.
http://www.parkerbows.com/index2.html