If you can find one used, in good condition, and the right color, then great.
But those things do wear out - the springs lose tension, the welds on the arms crack. New ones aren't that expensive (Mobile Tradition shows $164 for p/n 41611814312). And given what a hassle it is to install those things, there is some comfort in putting in a new one and being done with it for the next 20 years.
Alternatively, if your tube & arms are in good shape, you can buy just the torsion springs for $18 apiece. See p/n 41611810317 and 41611810318.