I need help with my homework. A little help please?

[arrigo]

Dave, the owner, and Sam, a builder, entered into a contract for the building of a gas station. During construction, Dave and Sam decided to amend the contract between them.
Explain whether or not additional consideration for the modified contract is required using the three sources of contract. Explain the differences between them.
In your opinion, what is the best source of law for contract modification?

[chason58]

I have no clue what your instructor means by "the three sources of contract."

But generally speaking, a contract modification requires new consideration. (see e.g. Demasse v. ITT, 194 Ariz. 501)

Modification of a UCC contract does NOT require new consideration. (UCC section 2-209). However, the modification must be done in good faith (2-209 comment 2; UCC 1-304).

[cruz50]

Except in Louisiana, Contract Law in the USA is based upon the Uniform Commercial Code. Any modification to the contract has to be done via the UCC. Since it is a change in the contract, the change and any consideration for it must be negotiated between the two parties, neither can "dictate" the change and the cost to the other.

The three ways that this might go is a change with no change in cost (consideration.) Example, Dave wants tan paint on the interior walls instead of white. Both paints cost the same. So no change in consideration is needed.

A change with an increase in cost. For example, Dave wants slab marble counters rather than tile. Since that costs more, he will have to pay Sam more for the work.

A change with a decrease in cost. Dave decides he wants to go with desert landscaping instead of grass and trees. Since desert is a lot cheaper, the consideration gets reduced as Sam can do desert at lower cost.