traffic isn't particularly high for that kind of rank, and can easily drop if you aren't developing properly. you should also look at the trend of the rank over the history of the domain. is it generally going up, down, kind of spiky and intermittent, and what is the source of traffic?
also, if you're looking to develop a site for a particular geolocation (say, australia), you might be able to check its alexa rank for just australia. even with an overall rank of xxx,xxx for all pages, it may have a xx,xxx or lower for your particular location. this means that although there aren't a lot of webusers in general going to the site, there are many aussies going there.