TrustFire 18650 3.7V 3000mAh 2 for $5.88

TrustFire 18650 3.7V 3000mAh Rechargeable Battery for LED Flashlight 2pcs/lot

http://www.aliexpress.com/item/TrustFire-18650-3-7V-3000mAh-Rechargeable-Battery-for-LED-Flashlight-2pcs-lot/557189125.html

Seems like a good deal as long as they are real.

I'll throw out the fact that my Trustfire 3000 mah cells, which had the hologram sticker, did quite horribly in a discharge test. One of them did 459 mah and the other did 2100 mah. Under spec, and no where close to equal.

Wouldn’t that make them dangerous to stack?

Exactly. ;)

Fasttech also has good prices on name brand batteries that are well matched.