I cannot help but buy calculators that I like. The other day I spotted a 1987 HP12c calculator in quite good shape. It was still working, but the battery low indicator was blinking all the time. The way the calculator looked, it had not been used too often - so the batteries may have even been original! These calculators' batteries really lasted forever. Also the clicking of the buttons is like the original - clear clicking, but softer keys than the ones of the new HP12c.
But the nice thing of this calculator is that it came with the best leather case.
This time in Burgundy - I had it in the past in brown color, but never in Burgundy!
I still don't know if I'll put it up for sale, or with/without the case, or with my own leather case.