In my experience, buying a used Porsche from a German dealership is on average significantly cheaper, opens a much wider spectrum of choice of color and option-combo's, with the same manufacturer's guarantee, and with not so much additional administrative burden. The Porsche salespeople in Germany are quite used to selling 2nd hand cars to non-German residents and they deal themselves with arranging your transit licenseplates. They mail or fax you the papers you need to have insurance coverage. It helps if you speak fairly some basic business German of course. Once in Belgium with your new toy, you have to take care of passing your car through customs (it's a stupid stamp you need to get), and afterwards register your car with Belgian plates and pay the astronomical taxes this country charges on supercars

. Other than that, of course you need to foresee a trip to the Porsche Zentrum in which you found the car. Depending on your travelling habits and the involved distance this will cost more or less. A nice approach is also to go with a friend in another Porsche, enjoy some AutoBahn stretches

, insofar traffic permits, and flavour the delivery of the new Porsche in this way. German dealerships also have the habit to make a sort of ceremony of the delivery, by hiding the car under a cover in the showroom and offering a glass of Champagne.
It's an option to consider, by all means.
Th