Regarding cheap priced extended batteries:
Samsung has just released a 3000mAh extended battery for S3. It costs 60$. This is the price for a hi-end li-ion batteries.
Our 4600mAh battery costs 87$ at the moment which is the market price if you would like to get the highest quality cells out there. We simply cannot sell cheaper, as these are the prices for the best materials at the moment.
Personal opinion from one of our customers: This solution is the best for long-term users, who buy a phone like S3 to use for several years. Tech geeks who change phones every 3 months don't even need an extended battery, and maybe, that's why they are ok with cheaper batteries, because they perform the same way as good quality but short-term.
We are glad to announce that now we are offering 6 different colored back doors (red, white, black, grey, brown, black and blue) for our 4600mAh extended battery for Samsung Galaxy S III
Purchase this battery / Free shipping worldwide
You can also order the back door in desired color separately here.