The TZ Brother tape lasts at least 10 years in my wretched climate. you can find deals on tape on Amazon and Ebay once in a while. I can buy locally at Office Max, too. I don't even buy the super strong tape. If you get the clear labels, they look the neatest, but I always have a white roll on hand in case I need to put a label on top of another label. You can remove the labels by blowing a hair dryer on them for a bit, but i find it easier and faster to just cover up an old label. One year I bought pink metal tags and the bright pink labels with white printing. It's kind of gaudy, but I like it.
This company:
http://www.metalgardenmarkers.... sells colorful markers. They used to be called Eon markers, and I like them more than Everlast because the edges are rounded and don't cut your fingers.
Kincaid makes stainless steel markers that really look classy but they cost twice as much. They do hold up better when you run over them with the lawnmower.