Cheapest I've seen was around $300 and it looked alright.
Like any milsurp rifle it depends on few factors. Manufacturer country, year, condition, history and bore (some of them are good shooters, but look really bad, I have a couple). If you are after an
Australian 303 in
Australia, where there's meaning, sentimentality and historic value, then yeah, you're going to pay... I think $700 - $800 for a rifle alone is what you will find these days. If you are just going to pay without being a d**khead and make it painless, get some photos, make your mind up straightway and move on it, then everyone is willing to move on price.
Don't take the d**khead comment personally too. I have bought and sold rifles on usedguns.com.au and holly crap man. Selling is easy, I have low tolerance for bs. If I smell something NQR, I move on... But buying stuff is an entirely different story. I tend to snipe at what I want and put up a wanted ad more often than not. The amount of people who literally call and just want to talk about their collection or "let me tell you how much it's worth to me" or "I am thinking about selling", why are you wasting my time if you're 'thinking'... Anyway, whatever price you get, drop a couple hundred - offer now and move cash now and message them to say it was transferred. You'll be fine