Joe's advice above re: robustness of goodwill valuation will be quite important.
Revenue will quite rightly see goodwill valuations on incorporations as a high risk, due to the fact that they are in effect an artificial transaction (the same individual retains ownership) and as the example above illustrates they can generate an ability to draw substantial amounts of cash from a company tax-free. So prepare to have to justify your valuation at some point.
Interestingly, there would be certain circumstances where the goodwill attached primarily to an individual, who in effect "is" the business - and simply saying the business has transferred to the company doesn't actually mean that the value of the goodwill has transferred.
If that person incorporated in the morning and tried to sell the shares immediately to a third party, they'd pay very little for them without also securing the expertise of the individual for a number of years, because they know that the relationships that generate the goodwill are between that individual and the customers, and not "the company" and the customers. If they buy the shares and the individual walks away, the new owner has nothing that is actually capable of retaining the customers.
Edit:
Lets say I'm Mandelbrot T/A Mandelbrot Cabinet Makers - I'm a sole trader, and it's just me and a skivvy. I'm a fantastic cabinet maker and demand for my services is huge.
I incorporate my business so that I am now Mandelbrot Cabinet Makers Limited - but the customers still come because it is Mandelbrot they want to make a cabinet for them.
If Shoddy Carpentry Limited approach me and buy the shares in Mandelbrot Cabinet Makers Ltd from me tomorrow, there's no way in hell they'll pay me anything for the name or the company, unless I sign a contract committing my services to their company for a few years, so that they can, over a period of time, leverage the goodwill that attaches to me, Mandelbrot.