Bart,
I've an Inter 17 for sale at the moment; 5 years old, but looks almost like new; a few signs of wear and tear that you would expect, but hulls and plates / rudders are in tip top condition and for a considerable saving over a new boat.
The 17 is a great boat. Let me know if you are interested - I'll deliver to NL for 1/2 the cost of the ferry plus petrol.
Cheers
Simon