Has anyone here purchased a ticket online through an airlines website - gone through and completed the transaction with one price shown, then been billed a different (higher!) price?

The case in point is China Airlines - they added an extra $50 in taxes to the ticket price! The order confirmation page lists the rather mealy mouthed disclaimer "The taxes listed here may be different from the amount collected for governments and passenger should pay the difference." But as we all know, the taxes collected very from airline to airline!