Reading this as being offered on the Gold Coast. Devil is in the details. I suspect is likely an "introductory rate" perhaps for a year but worth looking into. www.realestate.com.au/news/sweet-mortgage-rate-deal-secured-by-ray-white-surfers-paradise-for-auction-event/?rsf=syn:news:nca:gcb:article
This would be a white label product on which they are making no profit, or even taking a loss just because of the publicity it attracts.
If that's the case, the lenders loss is the borrowers gain right? I have some loans at 3.85. 3.49 would be nice. Yes I suspect they jack up the rates after a promotional period.