Despite your qualms with the OP, folks… ~50g out of the chest of a TIMED M+ aint it fam.
I believe COMPLETING a key should yield you a staggered amount of money based on the key level… so for example:
M+0 = 300g
M+2 = 400g
M+3 = 500g
M+4 = 600g
M+5 = 700g
M+6 = 800g
M+7 = 900g
M+8 = 1000g
M+9 = 1100g
M+10 = 1200g (continues onward)
And so on… and if you TIME IT… then add 50% to these totals.