Great price for the Bose 500 bass module given that everyone else is selling it for $600. That's about 33% off the RRP. Combine with Bose 500 soundbar ( https://www.ozbargain.com.au/node/507070) to get the package for <$1K.
I've check if the Bose stores can match this too. Turns out that TVSN is an authorised Bose dealer, so you will be able to get this price matched at any Bose store!
Note also this price (ex delivery) is lower than the recent black Friday price offered by Amazon.com.au. According to camelcamelcamel it sold for $410.
I recommend you grab the Bose Buzz700s it's a steal - https://youtu.be/a_TSR_v07m0