Hi Claire
The way I understand it, the permit just gives you a right to stay in New Zealand, but not re-enter. Since you are already in NZ, you can just apply for a permit for $280, which gives you the right to stay and work in NZ.
However, if you are to leave the country and re-enter before your PR is issued, you would then have to pay another $280 to get a visitors visa before you leave, so you can re-enter!
Essentially if you want to sort all that out now, you apply for a visitors visa, pay $560, and get both a permit and a visa stamped onto your passport now!