It is well known that technology depreciates in value with time. Todays iPad worth $499 might be worth $50 in about 5 years. Technology is moving at a lighting pace but some inventions remain price less. Like we had reported about the Apple’s first motherboard which was auctioned for $212,000.
Not just that but anything back then costs more than what is today.
Have a look at this infographic which might give you an idea and might actually make you save your old calculator :).