International Lettermail

Several years ago, Canada Post decided that the easiest way to disguise the impact of rising energy prices and inflation on lettermail postage was to issue a generic stamp for domestic lettermail--if you buy a lot of stamps, you don't notice a difference at all, but if you buy a packet every decade or so you no longer need to supplement them with another penny's worth of stamps for every year you don't use them. The real benefit to this program is that most people are in the latter category, so the populace is far less likely to rise up and overthrow the postal system.
The interesting hitch is, what if you want to use them for oversize/weight or international postage? Turns out the generic stamps are basically commodities now, with a floating value based on current service prices. Thus, two domestic stamps are valued at $1.22, but next year they might be worth $1.24, or $1.50, or whatever Canada Post decides to value them at. This isn't a problem at present, but the simplicity of the 'one true stamp' system breaks down when you don't have any other stamps and need to figure out how to get $2.10 for US postage to cover the weight of heavy cardstock and a CD.
(Also: making "other lettermail" cost twice as much as "standard lettermail" just because it's slightly heavier is, in a word, extortion. Still better than what private couriers would probably do, and a luxury service in any case, but I reserve the right to be disgruntled.)