Manker had a 30% off sale last November and I picked up one in a blue simply because I like blue. But I would only buy from Manker on sale.
Edited:
Recommend you use flat top batteries as the spring can slip off a button top. I would go with the Samsung 30Qs or Sony VTC6 - whichever is cheaper. I have also run the Panasonic/Sanyo NCR18650GA 10A 3400 mAh battery for better run time with slightly less output.
The price on the 30Q at LiionWholesale right now is $4.73 and will probably be your best deal. I would get as many batteries as you think might need at one time since shipping is high.
And welcome to BLF!
Edited #2: Check the BLF sales threads for deals on the A6 - especially BangGood Deals by Fin17. There is really no need to pay more than $20 shipped for an A6 from BangGood. Take Care!