What is the cost of a cup of tea? Much cheaper than a cup of coffee! Joking aside, as with all good questions, there's never a simple answer. Here's over-simplified attempt at breaking this down with your average British cuppa and a premium old tee (gushu) puer.
Cost per cup for a typical cuppa at home - about 15 cents or 10 pence
A typical tea for retailers will cost around $5 or £3.50 for 50 tea bags. The cost per cup is around 10 cents or roughly 7.5 pence. However, the price of sugar and milk which is necessary to make these teas more palatable. A typical cup will use one teaspoon of sugar and about 30ml of milk which equates more cost. For the sake of keeping this simple, let's not add the carbon cost which would actually be more than the basic retail cpc. Note that the above assumes a typical tea cup of 150-200ml as my mugs would typically require two tea bags for a decent brew, despite what most cheap cafes try to serve!
Cost per cup for premium grade puer tea at home - about 28 cents or 18 pence
A super premium cake of Puer tea is around $1 per gram of tea depending on supply/demand, although many good Puer should cost less than this. For a typical gongfu tea, 7 grams are used and around 20+ infusions of 120ml gaiwan. That's around 2 litres of tea! That's basically 10 to 12 cups of very high quality tea for $7. Brewing it down further and just further enjoying the mouth feel and huigan, we can get around 40+ infusions which is roughly 4 litres or 20 to 25 cups of tea. Many good gushus will last this long and still give and interesting body and sweetness despite now losing most of its aroma.
What's better value?
So upgrading from cuppas to premium grade Puer (if you can find it) is not that expensive overall. However, comparing cost per cup is actually comparing apples to oranges, so it makes sense to think about how you choose apples over oranges.
In my humble, biased opinion, I would be making time to drink a good quality premium Puer with all its aroma, flavour, mouthfeel, huigan and other complexities and whilst enjoying the experience with some good tea-buddies.
In contrast, those supermarket brand tea bags offer a nice, short, cheap and convenient tea break to be better enjoyed with some Scottish shortbread biscuits (or inferior alternative) - an experience which is a million miles away from enjoying Puer.
Both are great in their very own way and it would be overly hypocritical and tea-snobbish of me to say I don't occasionally enjoy a sugary sweet cuppa. However, Puer offers tea experiences on a whole different level and the multiple steeps offer a very good cost per cup value. Finally, as I age and mature, so does my taste for more interesting food and drink so it seems my bias keeps moving in one direction.