Everything is so fucking cheap in the US.
Antifreeze, here is like 12 bucks a litre IIRC.
And I think a gallon is a little over 3 litres.
Make those tanks. Like propane ones, but thinner and a bit taller.
Eh...I don't really buy the whole "ozone depletion" mantra for R-12. The way I see it, the governmant needed another way to tax in large quantities, and R-12 was it. You figure, every car uses gas, oil and (most have) R-12. So, they already tax gas and oil, so R-12 was the next logical step.