Anyone who makes a big deal about the price of either refrigerant must
be planning on going back to put lots more in. Your system will not
consume it like a car consumes gas, so why is that even an issue? The
average system holds maybe five or six pounds, so what's the big deal,
even if it all has to be replaced once in the life of the system?
Nothing wrong with 410 at all, and 22 will probably still be available
by the time your system needs to be replaced again. I would tend to
go with 410 just because the wider range of equipment choices at this
point is with 410.

The big deal is the old 10SEER systems that used to only that 5 or 6 pounds
are now gone, the new ones are 13+SEER and are holding 16 - 20 pounds of
refrigerent. The wholesale price of refrigerents have quadrupled in the last
year and a half.