Aero BR-23... The list price on the website for the rear replacement tank is $395.00 with no options. Tanks come with a Bronco specific sending unit and some hook up hose. There is an additional cost for EFI and you have to supply the in-tank pump for EFI. Usually a Mustang style pump.
There are a few other options than can be included. Skid plate option is one that is available. You can leave the mounting brackets off, so that you can weld them on yourself for a custom fit or they can mount them for you: stock position, 1" body, 2" body, 3" body lifts.
I have done 3 mass buy purchases on Norcalbroncos.com from Aero.
As a group, we have completed 5 mass buys over the years. Members here on Classic completed a Mass buy a year or so ago. (Suggest you do a Search to review comments) I personally have installed 5 rear tanks and one side tank (I don't like how it is mounted) from Aero. I have also done a NWMP tank many years ago. I like the Aero Tank. It is not a Pretty tank, but it is rugged.
Doug