$40 well spent I say, definitely not a tree decoration. Also, when you buy something good I think you get the extra value of being able to see how it's made, even take it apart, so in future you could make your own.
I'm glad you like the diorama, thanks, it will end up as a war game base, to begin with I was torn between having everything fixed down (diorama) and having everything as moveable pieces (war game base), in the end it's sort of half way - a wargamarama ... in any case once my kids get hold of it all and I'll spend the next year repairing it.
I'm building an extension to it at the moment, so it'll be twice as big. I'll also be having a play with various binders to try and recreate that vallejo stuff - sand's almost free and pva is cheap - how hard can it be..?
Cheers.