The Bot is an interesting gadget, and I have been mulling over the purchase of one. However, do the numbers....

The titanium bot lists for $99, the stainless version around On the other hand, a nalgene is what - $12? and a stainless cup that fits on it is about $8. For a fraction of the cost of a bot, you have even more water capacity and utility, with significant bucks available for other items.

You can play all kinds of games with differential weights and costs. About the lightest would be a recycled quart Gatorade bottle and a titanium pot (like the Snow peak 700) - cost roughly $40. Its only drawback is the relatively narrow mouth of the bottle if you wish to store items within it.