Here's my thought:

Good CFLs last a very long time (I've had a couple for 20 years) and
WAY more than pay for themselves.

Crappy CFLs last only a couple of years but still more than pay for
themselves because the crappy ones cost a dollar.

I prefer to pay for the $3 or $4 ones that last a long, long time
because even if it's just unscrewing them and popping in another one,
for the extra $2 or $3 a decade, let's go with not having to bother.