I reckon there is a good ten years left for Sandman's to be in favour as a collectible.
Still plenty of people wanting to live the dream. Whether the price has peaked? It would be in the zenith area but still might travel a little more.
The way the economy goes over the next decade and what if forced upon us will dictate where "toys" and their prices go.

Remember toys are the first to go when the going gets tough. Been easy sailing for quite awhile now. Everything turns eventually.