So....if you've tried to ship to other countries what kind of problems have you encountered?, and were these issues with the same group of countries?.....i'm not suggesting that all outside United States countries are a good bet to sell to. Its worth considering that some countries have problems with import duty....for example in the UK the import duty limit is only £15, anything over this has to be paid and in addition if Royal mail handle the import they apply a £8 collection fee to this too....
Norway impose duty from a 0 limit....so you can see that this can cause issues. Russia have long customs delays, India can be likewise, Brazil has a mixture of customs delays and theft from the postal system, Italy (the southern part) attracts recipients who make false inr claims, the North is trouble free, China was good but in the last couple of years personal imports aren't encouraged, and customs regulations are now punative, South Africa suffers a degree of postal theft especially if the recipient has an Afrikaans name. In the case of troublesome countries you can opt to use a signed on delivery service if that makes you feel more comfortable.