Do it yourself for well under $250. Tomcat bait station. Bunnings sold it, but it may have a different name now.
We had a serious problem with rats in one of our IP's a few years ago. Cost us a fortune with the pest guy as he couldn't get rid of them and the rotting corpses remained in the roof and the poor tenants had maggots falling through the light fittings. YUK.
Got hold of a Tomcat bait station and bait, from memory about $50 and placed it outside on top of a fence near the palm trees and pergola where the rats would enter the roof to have their parties, especially when it rained.
The tenant had to replace the bait daily for the first week and then weekly, now probably every 3 months. No more rat parties in the roof. The tenants didn't notice any dead rats in the yard either.
We discovered the rats had built their home under a pool in a neighbouring yard. If the bait didn't work, the council was our next point of call.
Sunshine