I've previously hired companies to spray pesticide at my property, however it's a very expensive cost as it could cost you more than $200. I've recently looked into doing it myself and it seems to be pretty effective. In total it only cost me $60 to DIY as it is currently half price at Woolworths.
Mortein Kill & Protect Do-It-Yourself Professional Outdoor & Indoor Surface Spray.
Same technology used by professional pest control operators.
Prevents insect infestations by killing cockroaches, ants and spiders for up to 6 months inside the home and 3 months outside.
Prevents the build up of spider webs. Not for use on termites.
Allows easy access to hard to reach places (up to 3m away for outdoor use).
Flushes out insects from their hiding places.
Ideally, apply entire contents as one treatment (covers 31m2).
Does it really works?