10000 for the carport from tom1978 is okay, but I would never pay that for the kemmler one... I'd rather go for one from TK Überdachungen. Or through myhammer with own effort.
I am currently thinking about whether to place two weather- and winterproof pavilions without sides - or one large pavilion without sides - one after the other. If it fits the house, it can be a nice alternative... but technically I haven't thought it through yet.
What is actually the big benefit of such a rack? The panes will probably freeze over anyway, won't they?
You can't really assume anything big either, can you?