That is way to pessimistic and fear mongering in a way.
There are some numbers available at http://wiki.openstreetmap.org/wiki/Osm2pgsql/benchmarks (eg getting it into EC2 in a day for ~30USD). Even just a week would be a pessimistic estimate.
I guess if all you want is geocoding, you could exclude a lot of data before importing it. Eg landuses without names, lots of single nodes that have nothing to do with addresses, etc.