Well I would recommend:
Nacra - F17
Hobie Cat FX-1
F16 Blade

Although I am sure none of these boats mentioned above can be had cheaply. The second hand F16s are going for what a new Hobie 16 would cost give or take a grand. As far as the other two classes of boats I have no idea what the going rate is for used.

The main thing to remember with whatever boat you end up getting is to have as much fun as possible.
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