The North end of the South Island has a lot of Microbreweries popping up. I had many a good pint there. Although I was not a poor backpacker when I was there, I found the price of micro breweries a tad on the high side 13-15 NZ $ per pint (I think, hopefully someone can confirm). The area was beautiful and many of them were really cool places to stop by and chill, it was always a nice treat.
Nelson and area was fantastic.
http://www.beertourist.co.nz/CraftBr...uthIsland.html