Replacement skid control ecu and HV battery in Aus

All new to this, after any guidance. Pretty sure I need to replace the HV battery on my 2006 Prius, and Toyota quoted me $5000 AU for a new battery and $3000 AU for replacement skid control ecu. Cars not worth that much. They suggested replacing the ecu first, and if that doesn't fix all the problem codes, then the HV battery would need replacement also. Original codes P3000, C1300, 2315, C2318.
I replaced the 12 volt battery, and in doing so got rid of all the lights on the dash till the next drive anyway. Then got a mini vci techstream and checked the codes, with codes C2315, C2318 not returning.
Saw a post about possibly resetting the ecu, so tried this but now get the error C1345 not learning linear offset. Tried resetting a number times unsuccessfully, presume problem actually stems from the ABS ecu malfunction.
Now have codes P3000, C1345 & 1310.
So planning on purchasing a used skid control ecu and replacing myself, hoping its not to hard, will double check the part number in the car before ordering, at least toyota gave me the required part no.
I'm also looking to get a refurbished HV battery from Prius Battery Exchange or Hybrid Battery Rebuild, anyone in Aus have any experience with them, or advice on alternatives in Aus.
I have no faith in Toyota at all, had all the lights come on, took it in for this as well as a recall and service, charged me a bit for a service and only when I picked it up told me the bad news. Subsequently started hearing the fan work overtime, and I replaced the 12V, as it was original, 12V battery test supposedly part of Toyota's service check. Any advice would be greatly appreciated