Note:
(a) Imagine 200万两 had been all gold (which is historically more expensive than silver).
(b) 1 liang 两 = 1.6 troy ounce
(c) Nowadays gold price is around $1,200 a troy ounce. Historic high (a few years ago) was $1,500 a troy ounce.
(d) For convenience, I will use the latter ($1,500).
(e) 200万两 2 million liang = 3.2 million troy ounces = $4.8 billion