The Boosters will remain an exclusive to the AX site. They are priced very nicely, though. A bottle of SXB will carry you through a whole bottle of SX and probably more. On their own, they probably aren't too much, but when combined with SX,they really provide that 1.5 or 2.5 dose, or a nice kick in the pants mid-day. As we say not to take any other stimulants while on SX, including some of those caffeine-laden pre-w/o supplements, SXBs may be that extra boost you're looking for without the dirty stim feel.