The USPS international letter rates are still quite affordable. Anything 3.5oz. or less and within certain size and thickness restrictions fall into this grouping. However, if a letter is greater than 3.5 oz. or it's too thick or the envelope is too large and too inflexible than it has to be sent parcel rate which can start at $9.45 for the 4oz. rate, $12.75 for anything 5oz. to 8oz. or $14.90 for anything from 90z. to 12oz.
Those are rates for places like the U.K., Europe, Australia and the like. It's a bit less for Latin America, Africa and parts of Asia. It's cheaper also for Canada ($2.00 for 3.5oz. rate jumps to $7.35 for the 4oz. rate), but still the parcel rates more than doubled since last January. You can still mail larger envelopes greater than 6" x 9" in size via the large flats rate which is not as high as parcel rates, but you can't mail it with very stiff cardboard. It has to be within the flexible regulations of the USPS to qualify. Those recent changes has made it harder to sell larger items like catalogue as Terence has encountered, large cover lots, large kiloware and the like. USPS doesn't have surface mail anymore for quite awhile so there's no other options.
And if you live outside of the U.S. and you're buying an item on eBay
, watch out for the Global Shipping Program unless you really want to see some high shipping rates coupled with higher than average customs fees even on items that do not require them. Since the hikes this year, I've found it cheaper to mail a buyer's items in two or more shipments rather than one. I never had to do that before.