We had Rob come out to do a building and pest inspection for us twice before we bought a house. It was very easy, they arranged the times with the real estate agent and gave me the details. Straight after the inspection (about 1.5 hours) he called to let me know of the major problems with the house and how severe it was. Within 24 hours I received the written report via email complete with photos. They gave us a 10% discount for using them the second time round - which saves you a bit of money as you may need to undertake inspections for a few houses before you're a successful buyer. Cost varies depending on the size of the house.
Approximate cost: $750