Cheapy - I think you're spot on comparing Lego to IKEA. There's a thing in psychology called the 'IKEA Effect' where, because you put effort into assembling the furniture, you value the final product more. There is an article in Psychology Today (https://www.psycholo...the-ikea-effect) that also makes that connection with Legos. Because the toy isn't just ready to go out of the box, even if all you do is follow instructions, you're brain rewards you for the effort you put into making it from chaos.
The real question is, is this psychological hack as bad as loot boxes or Fortnite? Would love to hear you and Wombat peck at each other about that.
Finally, thanks for doing the fundraiser for CTF - it's a great cause and the organization is very well rated by Charity Navigator (92.6%)