I personally value 125k MR at about $1500, assuming the points are later used in a 120,000 mile Travel Package. Since you're already in range of a TP, I'd probably hold onto the points since you have access to such an attractive paid rate.

Continue to pay close attention to the program. It's possible that the 2018 Travel Packages could change if SPG and MR are integrated. That might mean you need to redeem a Marriott-style TP by some date in the not-so-distant future, perhaps completing the stay by end of '18, although for now it's all speculation.