Seems that Fetch Mighty PVR boxes are $100 off RRP until 15 December 2019 and a number of stores have passed on this discount. Not as cheap as the refurbs but still a pretty good deal.
There are a number of retailers listed on the Fetch website https://www.fetchtv.com.au/packages/mighty/buy
Also available at the $345 price point at JB Hi-Fi - https://www.jbhifi.com.au/products/fetch-mighty-fetch-tv
Do these need to be connected to the internet constantly when using just the PVR function?
Also do the have wifi built in?
The answer is yes to your second question, it has both built-in WiFi and a single Ethernet port.
As for your "always constant connection" question, it's a 'kind of' yes.
It needs it for first setup and to register the device.
(You'll need to make an account to register, and $1 payment to valid a payment method)
It has trouble booting without an internet connection (from hard off), but it is fine afterwards minus TV guide and streaming services/Catch-up. The PVR function will work, but it will eventually need to download the updated TV guide info at some point. (About a week's worth)
Thanks for that.
Sounds similar to TiVo re the internet requirements.
I bought a 'refurbished' unit from Fetch on ebay for around $230 (with a code) a month or so ago, it's like brand new and comes with full warranty, highly recommend to save an extra ~$100 if you're in the market for one of these.