If you live in California the electric company (S.C. Edison) is paying part of the cost of these bulbs. You can get 4 bulbs for about $3.50 (that’s $3.50 for a pack of for, not each).
Otherwise, I have seen them selling as much as $2.50 each.
You have to look for them. Almost every store that carries this type of bulb with have the Edison subsidized bulbs but the retailers don’t put them in a prominent location.