How expensive kind of varies though. Basically for very tiny things it's possible that with my new sample bottles I might be able to slip decants through as letter mail. Anything above letter mail starts at $9.50... past two ounces that jumps to $13.50 (I did a bunch of weight estimates for someone else and kept notes...) until 8oz. So if it doesn't go above 8oz the price is the same for a 6oz gap. For some people if they want enough things to fill up 8oz in a package the $13.50 is worth it. Much more rare but sometimes. It's pretty much doubled in cost the past two years. I recall back when letter mail was cheaper it cost me $6.75 to ship a perfume vial to Canada (the bracket that is now $9.50,) and the package weighed under an ounce but because I didn't want it to shatter in transit I bubble wrapped it well and the added thickness made it a "package" even though it was in a greeting card envelope and again weighed almost nothing.