aaarims.com or thewheelexchange.com doesnt have the M3 Lightweight wheels.
21 Pounds is average weight for most wheels. im sure the OEM original ones that came on the M3 LTW were much lighter though.
17" Breyton Inspirations are around 21 pounds and are a popular wheel.
Keep in mind Replicas will always be heavier than the orginals.
But yes, that is a good price for 4 wheels, make sure to check the feedback rating of the ebay seller you wish to buy from.
Do some research on replicas on this site, there has been a lot of discussion on this subject.
Also keep in mind that the original bmw wheels of that style said "motorsport" around the edge; if you are going for a truly authentic look.
see here: http://app.infopia.com/Shop/Control/Produc...863558/vpcsid/0
i will probably end up with these:
the size i am aiming for is 17x8.5 all around so ive narrowed my choices quite a lot.