My dual occupancy has been riddled with termites on and off for the last 7 years. I have had two different pest control guys in that time. One sprayed to initially contain them, or so we thought. $1400 in 2001
The other guy used a hormonal bait, to great success. (At $250 x 6, you would want a great result) But as he explained. get rid of one species, and another may come along and find the tunnels and away you go again. In fact only two weeks ago, I ripped out part of the kitchen wall, because I could hear them tapping away. A stethoscope is handy for those hard of hearing, to suss them out.
I did some research, and I am about to try using False Sandalwood, in the areas of infestation. I managed to track some stock down in Windsor NSW
Check this out: Plant Extract Stops Termites Dead.
http://www.abc.net.au/news/stories/2005/11/15/1507502.htm
It only affects the flat downstairs. Upstairs is separated by 4 x 20 inch I beams, and no activity there at all. Fortunately, downstairs is not structural.
In about 5 years, I will gut the flat, and put steel frames in. Unless of course, the little buggers evolve and become steel munchers!!!