Troels 'Longspear' Brynjolf:
So Troels armour goes from
Fine Expertly Tailored Medium Leather Armour (Torso, Arms, Thighs, Knees) 20.4 lbs, DR 3*
To
Fine Expertly Tailored Medium Leather Armour (Torso, Arms, Thighs, Knees) 15.3 lbs, DR 5*...
Yes, assuming the initial weight of 20.4lb is correct.
Troels 'Longspear' Brynjolf:
...As lighten 1 is -25%, right?...
Yes
Troels 'Longspear' Brynjolf:
...And 2 shillings ($30) left, right?
Yes