There's no economical way to ship internationally with tracking. Often the least expensive way is to use First Class buy to pay $11.75 for Registered Mail, but because the package is checked in at every transport along the way it can be slower.
International Extra Services and Fees
http://pe.usps.com/text/dmm300/notice123.htm#1403102Otherwise, Priority (not the small flat rate box or envelopes) offer some tracking, Express should give you full tracking.
We usually go with First Class and insure if the item is pricey, irreplaceable or fragile. See the "Shipping Insurance" blog post for info on third-party insurers:
~~Shipping Basics~~
http://www.etsy.com/teams/7722/business-topics/discuss/10577585If you ship through courier services there are brokerage fees that often make them cost prohibitive (FedEx--pay online and you'll see those fees up front in the shipping price, pay at the counter in a FedEx location and your buyer will be surprised when the package gets to their country and they're are extra fees before they are allowed to get the item. UPS doesn't collect up front so the buyer always gets the nasty surprise.)