An early electronic pocket calculator
An "Adler 81" state-of-the-art pocket calculator bought in 1972 and well used for some time.
It has its own stitched leather case and it eats batteries! There is no auto-off function, so if you forget to turn it off - there goes another set!
The price in 1972? No less than £75 (about $175 in 1972)
As you can see, it still works and yes, I did remember to switch it off after I took the photo!