Enric, welcome to Photrio!
Hasselblads are great; if you never used one you might want to read the manual or watch a few videos how they operate. It will be your trusted photographic partner for life. Be aware of the warning message in Sirius' signature
The good news are, there are only a dozen or so lenses you can own, and you will not lose money buying into Hasselblad gear.
Before buying, please also check what kind of focusing screen is in the 500C/M. Chances are you will get the "simplest" plain screen, as shops tend to remove any fancier screen from cameras and sell them separately for up to 300-500 €. Despicable practice, I know. If the camera happens to have one of those fancier screens, best case a grid + split (which tend to be the most expensive), you are in luck. It will sweeten the €2000 asking price.
I mention all this because I think that a focusing aid is important with Hasselblads. It might not be important to you, but if it is, please keep the above in mind.
See below for an excerpt of the official Hasselblad catalog from 1989, to give you an idea of what was available. The grid+split appeared later and is not yet mentioned. It is in German but you will get an idea.