I'm half tempted to do that, though 500g is probably more than I'd use by its use-by date. I brew a lot of British styles, so S-04 could be my mainstay for many of those. I use that yeast the most often, with US-05 in 2nd place. I could easily go through a chunk of a brick in the 2-3 years I'd have. Maybe find another brewer nearby to split a brick.
I see it on Amazon for $77 a brick, which works out to about 15 cents a gram or $1.77 for the equivalent to a 11.5g packet. At that rate I could pitch 2.5 times that for the cost of a single packet.
Keeping it sterile all that time with repeated opening of the jar and scooping would be my concern.