They go for a bit more than the original price, according to this:
"Pricing varied by retailer, however Pickett did offer demonstration slide rules in 4 foot and 7 foot lengths: a 4 foot rule sold for $15 and the 7 foot rule was $25 in 1960. These were available with scales to match models N4, N803, and N1010 with the Ln scale added. These large rules were available free to schools which ordered 24 or more slide rules!"
