In Australia (you could get them in NZ too) you can buy the packs of 5 disposable ovulation tests from the supermarket or chemist that are around $20, they are the midstream urine ones.
The one that you probably saw was the saliva one that you can re use month after month (called maybebaby), thats why they are so expensive. The urine ones look for the LH surge that we each get when we are ovulating, but i have been told that you should probably test twice a day for about 5 days out of your cycle, so therefore it would probably cost you around $40 each cycle to test.
I just recently bought the saliva test (cost me $85) because i didnt want to go spending a fortune on disposable ones and possibly miss the LH surge anyway !
Hope this info helps !
Declan 7/12/04 & Taryn 25/4/07