Direct Tools is a TTI outlet, but there deals have never really been all that great.
Ryobi batteries direct from Home Depot really aren't that expensive - a 2-pack of 4Ah batteries is $99, and they've got 6Ah and 9Ah starting to enter the rotation.
If you're able to wait a few months, see what Black Friday is going to bring. I suspect that the SKUs that are showing on homedepot.com for the 6Ah and 9Ah multipacks are going to go active then.