I was bored , so I had a good look around many of the Farnell websites and it would appear that the pricing is based on the Base Price of $35 with any Import Duty already added. Here are my findings with exchange rates simply based on Google conversions.
Every site has it's own policy on delivery charge which has to be added as well as local VAT. I've yet to find anywhere more expensive than Thailand as not only do they have the most expensive Pis in the world, the shipping cost is another $25
(shipping to Thailand $8)
Some sites will let you ship to other countries. The Singapore site allows a Thailand destination, but neither the Malay or Hong Kong sites do. As you have to create an account on each site before you can see if the destination is okay, it became too much like hard work to do more.
If BMs would like to see this table populated more, just post your shipping costs in the local currency, and I'll add columns for shipping local and USD eqquivalent with a final Total Cost of RPi.
I haven't been able to work out how RS make up their charge as yet, but in Thailand, it's base cost + import duty + 'other'. It cannot be delivery as the site states 'free delivery'.