[khafra]

I'm trying to think of a dollar amount high enough to let somebody stick a tube into my jugular and extend my circulatory system outside my body for hours. I don't think I can count that high; unless I needed the money for fairly immediate survival.

[akuchling]

It's not as bad as it sounds, though 6 hours is quite a while. Platelet donation is done this way (http://www.redcrossblood.org/donating-blood/types-donations/...), taking an hour or two each time, and there are donors who make a platelet donation every two weeks. The blood cools while it's being run through the machine so you get chilly, but donors generally just sit under a blanket and read or watch a DVD for the duration.