、。
Until that point, I had never seen so much money.
Literal
I [topic-は] that time [until-まで-は], such big-money [object-を] see-have never-done.
The past-experience negative pattern [verb past]+ことがない means 'never [verbed].' Combined with までは ('until [time]'), this sets up a classic English pluperfect — 'had never seen.' Note the double particle までは marking both the temporal boundary and contrasting it with what happened after.