That's a tough one, I think there's only one and a half sets of Martial SGA in game...
Based solely on the protection values, I would assume it's worth somewhere between Adjusted Jaguar (M) and Angel (M).
I am aware of a set of Adjusted Jaguar (M) selling for around tt+8.6k, about a year ago, and afaik, unlimited male Angel now goes for around tt+10.5k to tt+13k...
So, again, based purely on protection values, I'd be comfortable paying around tt+9.5k, but due to rarity of this set, it could be valued higher, maybe as high as tt+11k (in some areas, it is better even than Angel).
Best of luck o/
Legends