The way it is "worth billions" would be computing the cost to reacquire it which is impossible. It is a stretch of course, and it depends on a strained definition of value.
That said, any reliable data from earlier is always good for filling out our understanding of how the planet has changed over time.
The additional data point really makes obvious how steady the Arctic sea ice was up to somewhere between 1990 and 2000: http://www.tjradcliffe.com/?p=1634 (just a quick replotting and refitting of the data, as the graph in the paper linked from the article doesn't really give a clear sense of how far in the past this new data point is).
That said, any reliable data from earlier is always good for filling out our understanding of how the planet has changed over time.