You should do *okay* for that much. As long as you look out for sales, though. Building a wardrobe will take some time so don't rush. Taking the time to figure out what your style and preference is will benefit you in the long run before you make unwarranted purchases.
Like Kayhill said, start with the basics.
You need at least two suits, navy and mid-grey (imo). Circulate between them every other day. Along with that, two pairs of shoes in black and brown. Allen Edmonds is currently on sale at Nordstrom's for $229 (select models). You can't go wrong with a black pair of Park Avenues and a brown pair of Strands or McAllisters. If properly taken care of, you should get at least five years of use from them.
A handful of tailored dress shirts should accompany the suits. The best colours to start with are white, light blue, French blue and if you think you can pull it off, pink. There are many other conservative colours available such as ecru.
Rue La La has a few Brooks Brothers Fitzgerald suits from their mainline on sale for $399. Half-canvas construction. For a bit more, you can try the Suit Supply route where their suits start at $399 (although their solids start at $469). Their stores offer a made to measure service. Again, if you pay attention to sales and promotions from high-quality men's stores, you can at times grab fully canvassed suits for as much as what Suit Supply charges for their suits.
If you check out the Marketplace of this forum or on eBay, you can find Brooks Brothers shirts for ~$25-40. At times Brooks Brothers will have their own sales dropping their shirts to around that price.
I can't answer to casual Fridays as I am not familiar with the concept. I assume it's a shirt and jeans day?