It is very necessary to study the experience of EMS crisis( EMS: European money system before EURO introduction)
And the third general Finance crisis (Asian Finance crisis) is also raised from such missallocation of capital( bubble of real estate market)
It is really a trade off between money policy maker and market, it is an interaction between these two player. The longer the expectation on RMB revaluation accumulated, the more difficult to defence such a peg policy. The cost is the central bank has to put more RMB on the market to calm such speculation, and to absorb excessive liquidity, they have to raise the interest rate, the operation will be very costly.