I don't know how prices compare between France and Belgium, but to give you a point of reference my 2011 black 4/4 sport with 29000 km on the clock was sold by Morgan France on my behalf in March 2016 for €40 000. Having said that, at that price it sold in less than a week. In the 5 years I owned it it gave me a huge amount of pleasure and no hassle at all. A great experience.
Mine was the same colour as the one you're looking a. I'd paid €43 500 for it new including the following extras; elasticated door pockets, 2 eared spinners, small rearview mirror, round wing mirrors, stainless chassis covers, tonneau cover, doorhandles, Moto Lita steering wheel, metal horn push and luggage rack.
I think the 4/4 is a great starting point with Morgans; we all have our favourite models, and of the classic Mogs i personally find that the 4/4 has the most charm. Do try and test drive a 4/4 and a plus 4 - the character is different.
The 3 wheeler is a real hoot to drive, but considerably less practical than the 4/4. It depends what you're after.We drove back to the UK a couple of times and down to the alps and the cote d'azur a couple of times with a decent amount of luggage and in relative comfort. I'm not sure that I'd have wanted to do the same trips in the M3W.
However, having said that I suspect that the next Morgan I buy may well be a 3 wheeler, maybe even an electric one.
Best of luck with your search. I hope you find the Mog of your dreams.