It’s possible to avoid a visa for stays <7 days (and save the $100 or so)… If you plan your flights right.
Essentially you enter under a Transit without Visa.
But you need to be transiting the Shanghai area (and nowhere else in China) - so going from one country to another (and Hong Kong and Taiwan count)
Eg. Sydney-Shanghai-HongKong-Sydney is valid
Last year I went to the Shanghai F1 (14 April this year) and flew SYD-PVG,HGH-HKG-SYD (booked via Qantas with the Hangzhou-Hong Kong leg on Cathay Dragon)
Best resource probably this one
I got out of Shanghai and spent a couple of days in Suzhou and Hangzhou (think of them as Newcastle and Wollongong geographically) just with high speed trains in between.
If roaming on mobile don’t need VPN but probably will for hotel WiFi (most chains used to VPN to Taiwan but they’ve cracked down on this). I just VPNd back to my home router.
Didi is the Chinese Uber - set it up before you go - takes most foreign CCs and translates everything including in app messages to English.
Seemingly still no way to setup WeChatMoney or AliPay (the two main QR pay apps) without a Chinese bank account - so cash it is.