Heh, here in the USA registered mail is an addition of $13.66, and you are required to go to the post office (you can't have them pickup those, even if you are a business.) A 1oz (up to 3oz) parcel costs $6.16 to ship internally, so we're at almost $20. Better to pay $10 more or so for DHL, as it's much faster.
Though, the USPS has been offering tracking for many first class in'tl packages, a huge change from before