I have 10+ bottles of 60ml Bausch & Lomb Renu contact solution in my travel cupboard right now - you can get them for 99 cents at any Target store in the USA, in the travel section. I've seen them at other shops (grocery stores etc) as well so next time any of you are in the US you should perhaps stock up... one bottle will easily get me through a two week trip. I usually wind up throwing the bottle away with solution left in it, but I won't use if if it's been open and unused for more than a couple of weeks.

I've had a hell of a time finding anything similar outside the US.