This article completely ignores the change in pricing structure for WDW and the MK, and the elimination of the ride ticket system. Sure, general admission in 1971 was only $3.75, but in order to actually ride the rides you then had to purchase ride tickets. assuming you wanted to ride 15 rides in your day in the park, that would cost you another $7-$9.50 depending on the rides you rode. That puts the real cost around $12. Which equals about $70 today. There was also only one park. If you want to spend one day in each of the four parks today it would cost you $305 or $76.25 a day (less if you bought discount tickets through
UT or another broker) and far less if you added additional days. The ugly truth is despite the incredible increase in number and quality of attractions, the cost of wdw park tickets, in comparison to inflation, has changed very little. At there cheapest in the mid 80s the cost in today's dollars was around $55.
I know it might be in vogue to point to price increases at Disney and complain about the evil giant corporation, but the reality is, an average middle class family can afford a vacation or two to wdw while the kids grow up just as easily as they could fifty years ago. Yes, it is a splurge, and most likely takes planning and saving, but it always was that way. And it is probably even more worth it today than it was back then.