I have to agree that it is only a deal if you can use it. Reselling older equipment can be a bit of a gamble on price or a long wait. On the other hand, if that white backdrop was a good quality canvas you might be able to recut it and make a sail out of it which could then be sold for so much more.

Looking in my own garage I see many of my brilliant ideas under a layer of dust waiting to be realized.

If you really think you could use enough of it, it would be a good buy. If not, it likely would be best to pass on buying the lot.