Hi Waipori they do come up for sale very occasionally but are not common.
You will read a lot about packages in overseas literature because in places like America they have huge hive losses, I think they average 30% or more of their hives dying each season. So they need just pure bees without extra equipment to re stock the hives as they already have the empty hives sitting there.
In NZ an organized package bee industry has never happened, other than for export, I believe we export between 30 to 70 tons of live bees annually.