I know its costly on some extent but if we all are paying 30 per year, I wanted to put a suggestion in to give the premium cachers something extra. Perhaps like a certain number of Pathtags sent to each person each year to aid in supporting more bugs traveling around. Or a coin, in small numbers the coin would be expensive, but in mass production of a certain coin, like a special coin for the year as a thank you, then it might not only say thanks but encourage others to jump on the bandwagon to start giving.
For example: If they only want to do the $10 then after 3 months they would get a pathtag, while when they reach their third tag they would get a coin to go with it. While the yearly would get 3 tags and a coin straight up.
Feel free to add or modify the idea, I just think it would promote the premium more, and thus promoting the site more.