Kiley just wrote up his take on the acquisition cost of Realmuto:
https://www.fangraphs.com/blogs/so-you-want-to-trade-for-j-t-realmuto/
He says some pretty stupid things like:
"Steamer projects Realmuto for 3.7 WAR in 2019, which I think can reasonably be pushed to 4.0 with framing"...moronic because Realmuto has been consistently negative as a pitch framer.
However, he comes up with a surplus value of
"$75 million asset value, maybe a hair lower, as both numbers are on the aggressive side". That jives fairly well with the ~$60M value we toss around here when we talk about Realmuto's trade value.
Then another odd comment...
"If we’re gonna say Realmuto is worth $70 million or so, a two-player package needs to be some multiple above that number, since the Marlins would prefer all of that value in one player. What’s the right number, though? Maybe 20% higher?" I have never seen any indication that MLB teams place a 20% penalty on a pair of prospects. Every trade I've analyzed suggests teams shoot for a prospect headliner worth over half the total surplus value, and then add in progressively lesser pieces until the surplus value of the MLB asset is met. This math has held true time and time again over the last 5 years or so.
Then he gets to the Braves:
"It’s been reported that, in July, the Marlins turned down an offer of RHP Mike Soroka (No. 25 on the Top 100) and 3B Austin Riley (No. 28)" That's a couple of 55s according to FG's board, which should be worth about $80M. He then suggests adding Muller, a 45 worth $10M+.
Why would the Marlins turn down a Soroka/Riley package now? Likely because Soroka is hurt, not because $80M isn't enough. Additionally, that alleged proposal was made during the 2018 season when Soroka was healthy and Realmuto's value was even higher than it is now.
If the Braves give up $90M+ in prospect value for Realmuto I will consider that a fairly significant overpay, and a very poor value acquisition.