Windshield Crack

About a month back i noticed a 8" vertical crack on the windshield of
my 2001 A4, meandering up from the place where the windshield viper
ends, . I cant feel the crack on the surface from inside or outside,
and hasnt travelled (lengthened) in the past month.

1. The dealer recommended guy who will put an "Audi certified, &
stamped' glass on is asking for ~$600/- for the replacement.
2. scouting around some other replacement companies quote ~$450 for and
Audi stamped, ~$300 for superior quality (claimed to be the same
windshield minus the logo, brands being named : PPG, Pilkington) , and
~$200 for safelite.

I am looking for views on what the difference of quality between
'safelite' vs Superior quality vs Audi logoed glasses.
In some forums, I've read some horror stories about 'badly installed
windshield'. People have gone to the extent of recommending not to
change windshield if the crack/damage is not increasing .
Thoughts, suggestions, experiences....


Thanks