Where To Buy A Tube Of Silver Eagles Direct?

You can't buy the regular silver bullion eagles from the mint! The mint does not sell these directly to the public!

Yep. To order bullion-grade bullion coins direct from the US Mint at the bullion market rate, you have to be an Authorized Purchaser. Requirements for being an Authorized Purchaser are quite tight, as the Gainesville website says; you need $10 million in capital under your name, be subjected to government audits, and submit minimum orders of 25,000 ounces of silver at a time. Here's the US Mint's list of authorized bullion purchasers, currently sitting at a grand total of ten companies: nine of them in America, plus the Bavarian State Bank in Germany.

Just like you can't buy hot-off-the-press regular circulation coins from the Mint; you have to get those via the banking system. The "uncirculated" coins the Mint sells for a hefty premium are specially made for collectors, just like the made-for-collectors bullion coins the Mint also will happily sell you.