I'm not in love with the BTV Marte valuation. Duran had a higher bWAR last year, over the past two years, and almost the same over the past three years. If he repeats his 4.7 for 3 years, that's 14.1 bWAR, for maybe $52M. Even if Marte does not decline at age 32-34, he gives us 13.6 for $47M. That's all good, especially since he fits so well.
But then we are on the hook for $44M/2 for ages 35-36, with a player option for $11.5M at age 37. In a vacuum, I'd rather have Duran than Marte. I can deal, but wouldn't add in anything extra.