As an e-bay seller I would second the comments made by Linda. If you have
any questions about the quality of a dealer's materials go to their Feedback
rating screen and do three things:

1] Look for negative comments - if there are any,  email the people who left
the comments and ask if they were ever successfully satisfied.

2] Look for heavy volume of repeat customers. This can be determined by
looking at the Total Number of Feedback comments and the Number that Count.
Multiple feedback comments from the same eBay customer do not count. We have
63 unique positive comments but a total of 190+ total positive comments.

3] If you are a registered eBay member, sign - in and when you view feedback
comments you will get the email address of the person leaving the feedback.
Write to a few of them and ask about the shells and service that they
received.

Unlike what has been posted here before, your friends cannot beef-up your
feedback ratings, unless you have a whole lot of registered friends!!!

eBay can be very safe and a lot of fun - pricing can be better than usual
dealer prices, but set limits for yourself and do not exceed them!! You
might want to consider only buying from dealers who posts more than 10
auctions at a time, and always look closely at the pictures. The last bit of
advice would be to email the dealer with questions about locality data and
condition.

For those new to eBay here is the Seashell Category Link:

http://listings.ebay.com/aw/listings/list/all/category4838/index.html