Why not the f1.2 then ???
'Build quality' (assuming you mean better/stronger) hardly ever matters to amateurs really as you don't give them that much work & punishment compared to a Pro who may be using it every day
But even to Pros, a lens 1/3 the price means you can destroy it 3x for the same price - and few would be so clumsy
As for better Bokeh???
I doubt if most togs really know what that means or appreciate the difference, and I do know that most clients would never have a clue even if shown the same image shot with both lenses
And quality???
How big/sharp should it be? My cheapie f1/8 looks great at f1.8 to A3 size
:shrug:
It's all too easy to thing most expensive is best, when all you need to be sure of is...
'Is it good enough?'
DD