You can buy these on eBay for around $10 or less nowadays.
The first personal computer I ever saw was a handheld Radio Shack thing that you programmed in Basic. I think you could use it to store phone numbers and that was it. It was maybe $100 or so for one in the early 80s.
Hey, that was big money 25 years ago. Probably $105 in today's money. Or maybe less.