They now include the software options factory enabled, as well as the warranty and factory calibration which is basically insurance. As they are about $600 AUD new (on special) and similar imported, $500 AUD seems a bit high. I'd pay about $400 max if I really needed one about $300 to get my money back on it. To beginners though $500 might seem a bargain as they aren't aware the model is becoming outdated or understand that Chinese scopes don't necessarily age that well.
Before I buy a scope I'd want to know it's ownership history, see it's uptime, firmware, options enabled, pass self test and self cal, runs all channels on a test signal as well as ensuring all the controls work. This sounds a lot of work, but with a malfunction or power supply fault it's max $100-$150 AUD in parts (and that's depending if you need something off it).
So if you want top dollar to get all buyers interested those are some tips on what you can do to add a little confidence. As you have only been on the forums 6 days and posted a dozen or so times, if you intend to sell it over the forums with virtually no information, it rings some alarm bells.