Not the cheapest, but has been a while since the last deal.
This is part of the Amazon mid-year sale.
Price is 20% off ($159 from $199 original price), plus combine with your favourite cashback for extra savings!
JB Hi-Fi has those speakers at same price if you prefer a physical store (although no cashback as far as I know)
Here is the JB Hi-Fi deal: https://www.jbhifi.com.au/pc-speakers/logitech-g560-lightsyn...