Bee pollen seems expensive per pound but nutritionally seems very reasonable. It is especially appealing to me because it is a carbohydrate source with equal amounts of protein. Spirulina is dirt cheap when you compare the vitamins in it compared to vitamins in store bought vegetables. Actually nutritionally speaking I think most green vegetables in the store are almost a waste of money, they are expensive and fresh doesn't usually mean much. Farmers say if you drop an ear of corn from field to fridge it isn't fresh anymore. Most greens are picked in the morning but would be much better picked at the end of the day, especially in hot nights, as the sugar or brix lowers during the night considerably, lowering the bioavailability of all the nutrients, lowering the protein digestibility and increasing the nitrogen levels. Plants picked during long periods of overcast may be holding toxic levels of nitrogen and be almost devoid of digestible protein and sugars. The less fresh the plant is the worse off all the nutrition is and the more chance for toxic levels of nitrogen buildup.
I say, why pay for vegetables when weeds are far cheaper, far more nutritious, far fresher and in the convenience of your own back yard. I tell people, why would I buy vegetables or plant a garden when god planted a delicious garden for me already?
On the east coast, the large stew clams are very reasonable and to me the most delicious thing on the planet, much better than the flavorless small ones.