If a domain in godaddy expiry auction has good Page rank, Domain Authority and Page authority, thousands of back links and traffic; Will it remain same if I buy that domain? Like how much time I have to resell that domain before these metrics start to drop down?
Yes, it will stay the same. I purchased many expired domains and I still have the metrics and the links.
Yes the seo metric remain same, they don't change at all, but if you want to drop down the metrics before selling you have to wait for a month.