I want to throw in my 2 jiao (Chinese cents) into this conversation as well about the forgery pu'er. As I've said before, it's nearly impossible to know to real from the fake. The box means nothing. The wrapper means less, and sometimes even if the tea has piao (a piece of paper with the emblem of the factory or something) in or on the tea, it also means nothing. The Chinese are masters as coping and forgery due to the lack of laws to prevent it, so the only way to know is by consulting some "master" or go to the factory yourself. Often, many factories keep some of the tea and age it themselves and this seems to be the best way to actually be able to "collect" more valuable tea. If you try this method, send someone Chinese to get it for you or they will more than likely cheat you because you are foreign.
I can give an example of a recent plight I've been suffering with a certain tea. I know of one shop here that can supply geniune Menghai Sheng Fangcha (the square 100g sheng version) that is aged around 10 years, and it's not so expensive. I guess 100g of it goes for about 20 bucks or something, but I get a discount because I know the boss well and I teach his son. This tea is becoming nearly impossible to find because everyone says that their tea is around the 10 year mark (the often say 1990-1993). The only real indicator is if the boss has a receipt from the factory and some proof, but you can definitely tell by the taste! It is quite smooth with only a slight bite like Sheng is known to have; it can be brewed for up to 30 times....if you have the real deal.
Anyway, so it goes that this is the only place I know to get this tea around here. I have even checked in Fangcun market and had no results. The stupid people there see "foreigner" and automatically assume that I'm good at tossing my wallet around with little care or knowledge on tea. They actually try to say that their shiny, new incredibly green Sheng is 10 years old! heh.
So, before you toss out a serious amount of money on 20 year old this or 15 year old that, get as much information on what you are buying as possible. Just because someone is Chinese doesn't mean they know diddly about tea or where their tea comes from. It's hard to trust anyone! Getting gipped a few bucks is ok, but don't take your investments too seriously unless you are buying new tea for storage.