Not to dredge up the eternal argument that will likely be the Pomeranz trade, but I'm just going to point out that this sounds a lot like the case for why we shouldn't have traded Espinoza: as a top 15 or 20 pitching prospect at the time of the trade, with a perceived ceiling of a top-of-the-rotation starter, he was a chip far too valuable to give up for someone with Pomeranz's history and question marks. Whether Espinoza never makes the majors, or blows out his arm and never pitches again (risks that you certainly take with any young pitcher), is kind of beside the point, because we know what he was at the time of the trade and can form an opinion on the trade based on that.
Interesting that you can look at $ contracts in an abstract way where the market rate at the time they were signed is all that matters, but disregard the immense value that elite prospects have in today's game.
A younger, healthier, and better player is always going to cost more, but I don't think that means the added cost isn't worth it, and paying megabucks to an old guy like Price in a few years means you have less to spend on a younger stud. Bryce Harper and Manny Machado will command a lot more than Hanley Ramirez in a couple of years, but that doesn't mean I wouldn't rather be writing checks to them than the latter.