Shares can be valued according to two methods:
Aggregate Purchase Price: also known as Aggregate Exercise Price, this is the entire price paid for all the shares
Per Share Purchase Price: calculated by assigning a single share price and multiplying it by the total number of shares to equal the total price
Even if the purchaser is buying all of the assets from a business, each asset should be assigned its own price for tax purposes. Note that some assets may be taxable depending on your jurisdiction.