The immediate post-war factory price was about AUD$500 in modern currency as I understand it; considering how many million SMLEs were made I don't think it's entirely unreasonable thinking that should be about the going rate an average condition SMLE rifle today. Sure, $1000 for an all-matching, 9/10 bore with beautiful wood is understandable, but seeing rifles which are not in great shape being offered at that price annoys me and also makes it hard for new people to get into Service Rifle shooting.
Sure, you can get rifles for less if you ask around, get lucky, or know someone who can sell you a rifle they're prepared to part with at a sensible price, but a lot of new shooters don't have those connections or that luxury, unfortunately.