Is this right?

Im going to be getting my custom cat-back made soon and I was going to buy my muffler, Someone on 3si used the dynomax Ultraflo 2.5 in dual 2.5 out on a firemans exhaust so I am going to get the same one...But tell me how these prices are so different,

$176.39 at summit

http://store.summitracing.com/default.asp?target=errors/404.asp&404;http://store.summitracing.com/eproduct.asp

$80.95 at carshopinc.com

http://dynomax.carshopinc.com/product_info.php/products_id/18017/17266

the first link doesn't work, but the second is for the ultra flow stainless steel (AKA SS) which is their best of the best, so just get it from the second site...