Star adventurer users can check out this quirky counter weight option:
http://www.darkframeoptics.com/produ...loverthree-red
Uses three cans so you don't have to lug counter weight around, plus you can have a beer once done for the night!
They quoted me £40 shipped to Aus ie ~$70
I need a little more weight to balance when imaging through a heavy Ep, so this is a great option.