Bauman-Bache, Inc., begins construction
on a seven-story office building and after three months demands an extra $75,000
on its contract. If the extra $75,000 is not paid, the firm will stop working. The owner of
the land, finding no one else to complete construction, agrees to pay the extra $75,000. The
agreement is not enforceable because it is not supported by legally sufficient consideration—
Bauman-Bache had a preexisting contractual duty to complete the building