I think that the pulsar study is based on a totally different timeframe (eg cycles per year, not 100 Hz). The pulsar study is looking for long slow galaxy-class events, not small black hole or neutron star mergers - from my limited understanding, the zippy merger that was observed with LIGO would not register on the pulsar study.
For interest, it seems that Australia could possibly have had a LIGO, but the Government was not able to finance it. From Wiki, "The LIGO-Australia plan was approved by LIGO's US funding agency, the National Science Foundation, contingent on the understanding that it involved no increase in LIGO's total budget. The cost of building, operating and staffing the interferometer would have rested entirely with the Australian government.[6] After a year-long effort, the LIGO Laboratory reluctantly acknowledged that the proposed relocation of an Advanced LIGO detector to Australia was not to occur. The Australian government had committed itself to a balanced budget and this precluded any new starts in science. The deadline for a response from Australia passed on 1 October 2011."
https://en.wikipedia.org/wiki/AIGO