Why bid for the car COE?

Dear Mr. Tan
I spoke to numerous people, but did not get an answer that is acceptable. I have been struggling to understand the rationale for the COE bidding exercise. Surely, a balloting for the COE could achieve the same objective of limiting the no. of COE. That is, if the government fix the COE price at a reasonable amount (which could be adjusted periodically), and use balloting for the no. of COE, the same quota would be achieved as well. 

Why is there a need for Bidding, which for whatever reason result in the sky rocketing of the price. In other words, the control of the car population do not have to result in the people paying exhorbitant prices for a cars. Unless the government is all out to make money, which I thought that is not the intent.

REPLY
my personal preference is to have a balloting exercise, instead of bidding for the COE. But our Government believes that bidding (and money) is the best way to allocate scarce resources. I do not agree with their approach, but they are the Government!

If we go on the balloting exercise, there is still a problem. Many people will ballot for the COE and resell the car to the highest buyer. So, the Government decided that the best way to prevent this "black market" is to go bidding in the first place, and let the market decide on who gets the COE.