3D is pretty old boat now, so you don't want to pay more than $300.
Learning to roll a whitewater boat will be just fine for learning to roll a seakayak. It's the same technique, just a slightly different feel. Also you can learn a lot about bracing and staying upright. If you have a small boat you will be more likely to go out and play in rivers, rock gardens and surf and become a better all around kayaker.
A good video for teaching yourself in a white water boat is Eric Jackson's Rolling and Bracing video. It will teach you a lot of essential skills and most people are rolling on their own within about a half hour.
Rescue / Throw Bags
Full Size Sail Rig
Classic Freestanding Rack
YakCatcher Rod Holder
Touring Kayak Paddles
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