You do not. They're cheaper
here.
I like competitive open markets (in all things, not just Bullion); but as of time of post:
https://agoracommodities.com/product/silver-american-eagle/Silver American Eagle - $23.88 - Delayed 4 weeks [no mint year mentioned]
http://www.amagimetals.com/american-silver-eagle.html1 Oz 2013 American Silver Eagle Coin - $24.09 [+0.21] - Availability: In stock - Shipping Immediately [2013]
I'll leave the postage comparison up to others (I've never used their services and have no reason to change that atm.); however as Amagi Metals actually have the product on hand I'd say they are the cheapest on the Internet.
EDIT:
https://agoracommodities.com/shipping-information/"The standard shipping charge is $17 for orders below $5,000."
More than postage from Amagi Metals (around USD$10 USPS International Letter option) so adding postage Amagi Metals is actually cheaper.
Agora is still cheaper. If you check their thread on this forum you'll see that their shipping is $5.60, they just haven't updated their website.
PS - nobody mentioned shipping. The claim was that Amagi has the cheapest silver eagles. They don't.