Some pu-erh tea can be over 50 years old. ... It is a good idea to hold on to these as they will get better and better each year. ...People will pay thousands of dollars for rare pu-erh teas that are 30 years old and up.
here is some example :
So far this one is the most expensive Teacake I know. Do you know how much is the price ?

Menghai, Raw Teacake , 50s (more than 50 years)
Estimated market price at as 1st May 2007
RM 30,000 (USD 8,700)follow by

Menghai, Raw Teacake , 60s (more than 40 years)
Estimated market price at as 1st May 2007
RM 25,000 (USD 7,250)and

Menghai, Raw Teacake , 70s (more than 30 years)
Estimated market price at as 1st May 2007
RM 7,000 (USD 2,050)