I don't think it's suspicious...you will see why when the bill for the shipping comes.
LA has a 14 day guarantee on their livestock. LA QTs a lot of their livestock (depending on the source) before they ship out.I thought the prices were suspicious because many other places will charge around $35+ for shipping as well because all shipping is overnight to ensure live arrival.
But other sites, such as foster and smith's liveaquaria.com charges $2.50 (rummys) and $2 (cardinals)...
But I guess if no one's had any bad experiences, I wouldn't mind going this route for stocking my tank once it's established.