No one treehouse, so no one answer. Sorry.
$650, +s+h = out to $800 by:dude
timber
in entrance it is in the treehouse!
Try looking at Home Depot or Lowes for ideas. You can also purchase crafting books and magazines for ideas on how to build a treehouse for your kids.
If you don't have a tree it will just be a house.
It cost about $550 million to build.
it cost 1p to build this building
It cost about 9,000 pounds to build a Spitfire.
It cost about 300 million dollars to build your welcome
You can definitely build one yourself for less than that. With the slowed economy you can probably hire a carpenter to build a simple 8' x 8' treehouse for around $1500.
About 10.5 is the cost to build
It cost 1,000,000 dollars to build the Rosenberg Castle.