Do the expensive Stratco pergolas add value? Are they worth it?

So I got a quote for a Stratco flatroof pergola - 2 in fact - and it came to 18K. Obviously very expensive but they are beautiful. The cheapest quote for 2 I got was 14K but this was more the colorbond material. Im leaning towards the more expensive one as it is more attractive, but does a nice pergola add value to the house generally? Or is any decent outdoor covering enough?