For price matching, it needs to be the exact same model of the product. And I believe you just need to contact them prior to ordering, and they will give it to you for that price minus 5%. Not 100% on the exact procedure, as I've never price matched. bigalsonline has always had the best price for everything I've ordered so far.
I've also ordered several times from Dr's Foster and Smith, and have very good experience with them as well. And they are not only fish, but any other pet needs such as dogs, cats, rodents, birds, etc. You need anything for a pet of any kind, they will more than likely have it.