standards for giving out blocks of IP addresses

Umm.. don't bother. Let's think this through. 2Mbits/sec of bandwidth
will only sustain about 40 56KB modems doing a simultaneous download.

This misunderstanding of bandwidth usage has been propagated many times
before... one can only hope that it will go away someday.

Some *real* statistics... one of my rural POPs (translation: heavy usage)
has 620 subscribers and 112 V.90 modems. *Real* bandwidth usage over the
last month: 515.3Kb/s maximum, and 233.7Kb/s average. Clearly no where near
2 Mb/s. It also gets by with a /25. My urban POPs have one-half to
two-thirds this usage.

inbound cash flow of only $8K/month

Well, it would be $12,400/mo at 620 subscribers. That's plenty for a
mom-and-pop, which can easily handle 620 subscribers. There are many ISPs
in the country that are this size or smaller, some of which are downstream
from me.

Our policy in this situation would be to allocate a /24 to the customer
initially, and route more as needed.