According to the specification laid out in Revelation 21 16-18 (here), the walls for the new Jerusalem are colossally expensive, almost beyond comprehension. I’ve assumed:
– four walls of 1,400 miles (2253km) in length, with height and depth of 200 feet (61 metres).
– jasper density of 2.6 tonnes per cubic metres, and a cost of $20m per tonne.
The cost of the walls alone (excluding the City of gold, or any of the foundations) would therefore be $670 quadrillion. If we assume that on any given day there is $8.3 trillion in circulation, then you would need to gather every single dollar in circulation every day for 221 years. Just for the walls!
The QS is going to be busy in the new Jerusalem.