My friend said it costs him on average .20 a cup
I think the key here is
"a cup".
When most barista refer to "per cup" they will probably be talking about a double, since many don't serve single shots. If you purchase a "shot" of espresso, nearly everywhere in the US, it will be a double.
This means unless he is roasting his own, he's using a really low grade espresso. That would be why it is .10 per shot, .20 per cup. On the other hand, if he roasts his own, or is talking about per SINGLE shot of espresso, he is using some mucho-primo espresso!
But let's explore this from the "How many shots per pound?" perspective.
In reality you have to assume about 10-15% wastage of coffee, so if you have 453.59237 g only ~385 to 408 grams with which to work. So at 7 grams a shot you are getting 55 to 58 shots per pound... Although I don't know many who really use 14 grams per double...
it's safer to assume about 50 shots per pound.
Many shops do 17 to 20 g doubles (or 19-21 g triple), so if we take an average and divide the 453.59237 g by an 18.5 g shot we come up with 24.52 doubles, or about 49 single shots. If we include a reasonable amount of waste here, this is a much easier target to hit--even at 16 or 17 g per shot.
For us, we used to average about .37 per shot actual cost, and although we roast our own now, we source very select coffees and, factoring in bean and roasting costs, we average about .29 per double. Most of our shots are approx 17 grams.
I guess the real question is, "What was the friend actually saying?"