Hello! I am always able to find good deals on petite sized suits at major retailers these days. They always have sales going on, and they have to compete with stores like Marshalls and TJ Maxx. So even their everyday prices are good. You should have no trouble finding one for $100-200.00.
Check out Filenes, Macy's, Lord & Taylor, etc. You might even be able to find a decent suit at Sears. It's worth a look! I don't recommend purchasing a suit online, because you won't be able to get a good fit. Take the time to look in stores & try on a bunch until you find one or two you're really thrilled with. And if you purchase ones that are interchangeable, and coordinate with one another, you expand their possibilities. Combining slacks or skirts with the jacket from another suit can often stretch your wardrobe!