I'll have to read the thread.
Have you read Thomas Pikketty's Capital in the Twenty First Century?
He came up with some equations to account for these 'waves' to do with private/public capital ratios - there's a certain logic to it that makes the waves inevitable.
Yes there was depreciation, but the Renaissance coincided with the growth in the power of Kings and central government bureaucracy (centralisation of states around the time of the 'New Monarchs'), so that debasement was counteracted by the issuance of New, High confidence currencies. The hegemony of the Spanish and New World rare metals plunder had a lot to do with it.
In fact, a lot of the economic growth of the Renaissance is to do with the combination of stable currencies and banks willing to issue it (esp. Florentine) in the form of debt, vastly multiplying the level of liquidity in the system by several magnitudes.