If there are (or will be) investors willing to invest at the initial IPO price, how can you say that price is going to be 'artificially high'?
The IPO investors, themselves will be buying in the hope of making a gain, if their analysis/forecasts/judgement is wrong - it won't be Goldman that screwed them, it will be failure of their own judgement. And also their own willingness to join to 'bubble' to make a gain.
Also, if Goldman are the underwriters of the IPO, and they fail to sell the shares at the 'artificially high' price, they will have to take on the shares themselves. If such a high profile IPO is not fully subscribed, it won't reflect well on Goldman, so setting an artificially high price, is not in their interest, but setting a marketable price is.
The IPO investors, themselves will be buying in the hope of making a gain, if their analysis/forecasts/judgement is wrong - it won't be Goldman that screwed them, it will be failure of their own judgement. And also their own willingness to join to 'bubble' to make a gain.
Also, if Goldman are the underwriters of the IPO, and they fail to sell the shares at the 'artificially high' price, they will have to take on the shares themselves. If such a high profile IPO is not fully subscribed, it won't reflect well on Goldman, so setting an artificially high price, is not in their interest, but setting a marketable price is.
Also empirical evidence suggests IPO's tend to be underpriced as opposed to over priced, to allow for gains on day one. (see http://en.wikipedia.org/wiki/Initial_public_offering#pricing)
With Goldman themselves having $450m in facebook, this also adds some credibility come IPO time, as GS themselves will have 'skin in the game'.