I never really figured out why the price jumps. Unless it's just bigger margin which would be totally justifiable since it's still a fair bit below what it should cost for these things. Those shots of the chesterfield are drool-worthy.
We buy our material, pay labor, and ship in a foreign country but receive our money in USD. The Forex and tax demands change frequently and we are at the mercy of them. I have kept a consistent margin requirement since I started, though.