Back in 2014, PhotoDave219 (who used to post here and was often a good source of information) stated that Frozen at Epcot was approved at $75 million (after a significant 40% cut apparently). I believe this included the ride along with new restrooms and meet & greet facilities. I don't know how much was spent on the ride itself, but one would think a significant portion. Perhaps $50 million, though someone who knows the exact amount can clarify. The reason I bring this up is to give some perspective about what that budget gets you in the modern era. A very small handful of somewhat advanced face-projected AA's, and a lot of barren corridors with projections on the walls.
The original Splash Mountain at Disneyland by contrast also had a reported budget of $75 million. Most animatronics were reused, but they still had to create an entirely new building, ride system, scenery etc etc. It was still a very expensive attraction for the time, but imagineering was far less bloated and much much better at managing costs back then.
I'm not sure what the budgets for WDW and Tokyo Splash Mtn were. They share similarities but largely have very different and more detailed scenery, a somewhat different ride system, and a handful of more advanced AA's (though slightly fewer in quantity). Regardless of the version though, if modern Disney were to gut and replace most of the interior Splash Mtn scenes with the same amount of quality scenery and number of AA's (assuming their creative teams even have the capacity to do so anymore), it would still likely cost at least 3-4 times more than the original's $75 million.
WDW Pro (whose source was correct about Splash Mtn and other attractions being looked at for overhauls several weeks ago) has thrown out $50 million for this PATF overhaul. I don't know if this was an assumption, or a number shared by the source, but I assume it was the latter. That in and of itself is a pathetic amount. That's comparable to what I ballparked for the Frozen ride, but stretched far thinner due to Splash Mtn being an immensely longer ride with far more scenes to have to deal with.
The alleged budget I saw was even lower... Which is a disaster if true, but honestly either of these amounts is absolutely unacceptable. Even with the best and brightest creatives involved (assuming there's even anyone left at the company who could match Tony Baxter and the original Splash Mtn team), doing justice to the original scenery detail and animatronics in Splash Mtn would require a budget of several hundred million.
