I get 6,000 mAh of power from the 4 Touch Pro 2 batteries I have. Pop one out, and put another one in I'm glad they have an option for you guys that don't want to go through that hassle though. $70 seems reasonable too for that much juice. However, after some of the reports I've been reading, in regards to these batteries testing out at a lot less capacity that what they are rated at, I'm a little skeptical of them.
I have purchased three stock batteries and two chargers off ebay for less than $25.
I have one charger at work, one at home. My battery lasts 1/2 a day and I just plug in a fresh battery before leaving work.
What these battery manufacturers need to do is bulk out the ENTIRE back case, not just the area where the battery is. They can use the empty space for storage. Make replacement battery case thicker all the way around, then add a microSD card storage compartment.