Don't want to put a damper on anyones plans BUT he says it's identical to the original. A spoiler is one thing, it's solid and doesn't need to flex/bend. However a bumper needs to be able to flex and give a bit without cracking itself or the paint on it.
How many times have you (Honestly[

]) scraped the underside of your front splitter on a kerb unknowingly, especially with lowered suspension? I can almost guarantee that if you were to look at the underneath of the bumper you have now you'll see evidence of this.
At the end of the day you get what you pay for but remember you could be spending the money you're saving on getting it repaired/resprayed a few months down the line if it's fibreglass.
I don't care what anyone says you CAN definately see the difference between original and fibreglass items (I know having spent a few quid on tat for past cars[:I]).
Cheers, Jim