Benni,

That 16 doesn't look too bad for $900. However as said lots of times before, a gallon of water an hour is a lot for a boat to leak. Is that in both hulls or just one? Have you seen this for yourself? As the Prindle doesn't have a platecase (and in the abscence of any hull cracks or damage) the leak(s) has to be at a fitting or the hull to deck join. This will be fixable in all cases, if you can find it (and want to fix it).

In your position I'd go for the boat but get someone who genuinely knows about boats to look it over to make sure the hulls really are sound and that we're only dealing with a dodgy fitting or similar.