@Kar *********
when are you expecting your house to go up for sale, or if that's underway, when do you expect it to be sold (approximately - 1st, 2nd qtr etc)?
From doing an online search here in Australia, at the time of application, you'll need to show a minimum of the equivalent of 800k Thai Baht (per person) in your Australian bank account, for a minimum of two months. As you don't have the funds until you have had the proceeds of the sale of your house deposited in your Aussie bank account for that minimum of two months.
Once you lodge the Visa application, as long as you provide all the requested documents, with no mistakes, I don't think it takes much longer than three weeks, maybe not even that unless they're very busy, too get approval. It might mean finding alternative accommodation, such as living with a relative for about three months from the time you vacate your house (allowing 2 months for funds to be in your account, plus Visa processing time).
As another person suggested, you could create an account with the Embassy or Consulate and start an application to find out all the current requirements, then delete the application and start another one when your funds are ready. The online search I just did, shows info going back over two years (2023), so there might be slight changes to the requirements.