So I just asked some carpenters from my circle of acquaintances: they recently actually built a shelter for three tons, customized it for the customer, and painted it. That cost €600. Something a bit simpler would have been cheaper.
We bought this from Keter... but it is not yet in use, as it was bought in winter (but it is already standing against the house wall and is built very sturdy)
Hi, the company Siebau (also make carports, garages, etc.) offers something like that and will paint it for you in (almost) any RAL color. So if you want something a bit colorful, it might be worth a look. Regards, Andreas