if I had $400,000 to sink into a website it would probably do much better than that one is.
it has been online since 94 and only has a PR of 5? my sites that are a month old already have over 20 X as many backlinks as that site does (which there site is only at 40 in Google right now)
i would say since many of their inner pages are not indexed
and they have been online since 94 with only 40 backlinks that is likely not a 6 figure business. in fact on $5,000 I bet I could design a site which had more link popularity, better layout, better branding, etc.
they got all those other sites in that package too, but I am not usually a fan of buying used sites.