Yes. Where do you think the resale market gets it's inventory? What was once a new computer is later a resale computer.
This analysis is often used. For example, currently the prices of used cars are at an all time high (meaning used cars are selling close to their new car price than ever before). Why is that? Pretty much most economists agree it's because (1) ~5 years ago we were in a recession and sales of new cars were at a very low, thus the supply of used cars is low; (2) ~5 years ago, lots of inexpensive used cars were destroyed in the cash for clunkers program, again reducing the supply of used cars today; and (3) many middle-class families haven't seen a wage increase in a long time, thus more of them would buy used rather than new, so demand of used cars is higher. Does this let us know anything about the new car market too? Yes it does, this shows that if prices of used cars drop over time (again, speaking in a relative manner), then we will know how well the new car market was doing today.
So the data from the used car market is very insightful into the market overall - both new and used. The same is true of computers. Analysing the resale markets gives a lot of great insight into the overall market.