They'll re-sell a a price below cost

It's a set phrase. Here's the entry from the Oxford Superlex:

manque à gagner loss of earnings.

For your context, I also like this version, from Termium: shortfall (they have a number of other possibilities, but not as suitable for your text)

<<opportunity cost. The benefits lost by not employing an economic resource in the most profitable alternative activity. For example, the opportunity cost to a self-employed person is the highest salary he or she could earn elsewhere. Economists use the concept of opportunity cost to decide whether or not the allocation of resources is efficient. In the example above, if efficiency is judged by income alone, self-employment is efficient only if the income earned exceeds the best alternative salary, i.e. the opportunity cost ...>>
[A Dict. of Finance, Oxford]

<<Expected opportunity Loss (EOL):
The amount you would lose by not picking the best alternative. For any state of nature, this is the difference between the consequences of any alternative and the best possible alternative
[http://www.cs.usask.ca/resources/tutorials/csconcepts/1999_6...]

<<Opportunity Loss or Cost The value of a lost chance or a potential profit that was not realized because a course of action was taken that did not permit the investor to obtain that profit.
The actual or expected cost of following one course of action measured relative to the most attractive alternative. opportunity loss will not be reflected in an accounting statement.
An example of an opportunity loss might be the $20 per share profit forgone by a covered call writer who sells a call with a $45 strike price for a $5 premium, only to see the underlying stock jump to $70 in response to a take-over bid.
[http://www.hi.is/~joner/eaps/wh_econc.htm]