The Canadian dollar and the us dollar are not the same value. They are both worth $1 in their respective countries, but its not worth $1 in the other country. Both an american and a Canadian would be paying the same value for a donation feature, the number would just be different.
Please do not tag Server Admins either unless it is absolutely necessary. In addition, that makes zero sense, as the CAD and the USD are not equal in value, as you just stated. Why should they be the same price? There are based off of conversion units, while taking into account changeover fees and other feeds I believe.