There was a thread on a similar topic not too long ago:
Particularly Post #4
EDIT: Perhaps you should read the seller's "Feedback Reviews" posted by consumers like yourself. I briefly looked through it, and the overwelming majority are happy with their purchase, but there are a few people who are not so happy. Again, the old adage comes into play here with Ebay - "You get what you pay for."
Not only that, but IMHO there is a lot more technological know-how regarding suspension systems than, for example, exhaust systems. Personally, I would much rather pay for something that I
know is going to work and perform, instead of
hoping I made a decent purchase.
Just be careful.