Try to find the spot where the photographer was standing.
Balmain Post Office and Court House (by James Barnet) built 1886. But there is no Town Hall beyond - built in 1888 (originally also with a dome) - www.leichhardt.nsw.gov.au/Community/Community-Facilities/...
So photo is 1886-7. So far ...
GoogleMapsStreetView - goo.gl/maps/bf3IZ
NB - *missing notes*
"BRUCE" on the cart
Dog in the gutter
11:10 on the clock
In March 1887 there was no clock or fence - " ... The unfinished aspect of the grounds which make it a fit promenade for goats and the reproachful aspect of the space for the clock in the big tower which looks as blank as the face of a larrikin when he has got a month instead of a fine, are in a fair way of being remedied ... " - trove.nla.gov.au/ndp/del/article/132310057
John Rae (no less!) wrote that tenders were approved in April 1887 - trove.nla.gov.au/ndp/del/article/132311429
Building opened 20/08/1887 - full description in the SMH 22/08/1887 p.4 - trove.nla.gov.au/ndp/del/article/13650287
" ... In the tower is a clock, having a dial 7ft. in diameter,
supplied by Mr. Tornaghi, of Sydney, and the face is illuminated by night. ... "
So earliest date for the photo is mid 1887.
The Balmain Town Hall foundation stone was laid in January 1888 - trove.nla.gov.au/ndp/del/article/132306797 , and opened in August 1888 (phew that was quick!) - trove.nla.gov.au/ndp/del/article/71102029
According to trove.nla.gov.au/ndp/del/article/71290783 , the courthouse (alone?) cost 17,000 Pounds, "rather an extravagant amount to spend in such a direction". Equivalent to $101,320,000 now, by www.measuringworth.com/australiacompare/