Much of that stuff looks collected, not crafted. The only things that clearly looked crafted were some of the stands that looked like castles and some of the wall panels, and they all looked like XPS foam cut with a hot wire then painted. Except maybe the whale. That would have used a hot knife, instead, and a bit more skill.
Cutting XPS foam with a hot wire is easy to learn, and relatively inexpensive. Spray painting and dry brushing are also easy to learn. What I'm saying is, get started, if you want.
(Do you have reason to believe those figurines were hand crafted? They didn't look so to me. Of course, if they were, that would certainly justify your sentiment!)