Try the Emotion Bliss ($529; emotionkayaks.com). It's a wee bit over your price range, but $529 for this kayak is a steal. Specifically designed for light to mid-weight paddlers, the polyethylene plastic Bliss is a surprisingly swift and nimble boat thanks to its shorter length (10', 10") and trim beam. It has an adjustable back seat that folds down to store dry bags in the stern and a rear fishnet pocket to store water and lunch. There's an adjustable foot brace to customize the fit and, at only 37 pounds, you can wrestle it to the top of your car by yourself. Plus, it comes in cheerful colors: lime, blue, red, yellow, tangerine, and purple.
Option number two is Necky Kayaks Looksha 12Si (with rudder, $1,299; without rudder, $999; neckykayaks.com). This day-touring boat has the same features as Necky's Looksha, but was downsized to fit a woman. If you plan to spend more than a few hours at a time paddling, the polyethylene Looksha 12Si has some comfortable features: an optional rudder system, a high-volume bow to keep you drier, and a cross-locking stern hatch with a neoprene cover for easy gear storage. At 12'1" and 49 pounds, it's a little longer than the Bliss and quite a bit more expensive, but it's a solid boat.