Here's a 1973 magazine ad for the Electronic Brain - a very basic calculator (by today's standards) made by Commodore.
It is actually a Minuteman 3, one of the earliest pocket calculators. Hard to believe, but these were so unique in 1973 that we would play with them for hours. (We didn't have this one, we had one of the original Texas Instruments models).
Also hard to believe - adjusting for inflation, $49.95 is almost $250 in today's dollars. These days, more sophisticated calculators are routinely given away for free.
If you're interested in old calculators, here is a great site with pictures and descriptions.