Consideration is one of the four elements required to form a valid contract. In which of the following situations would there be good consideration?

1)

Abby accepted Billy's promise to buy her a watch for her birthday.

2)

Nelly paid Casey $50 for his vintage watch even though the value of the watch was $5000.

3)

Sally had worked for 1 year for Tommy and then Tommy promised to reward Sally with a watch for her excellent work.

4)

Kelly completed her project on schedule in accordance with the terms of the contract after Manny promised to pay Kelly extra money for her timely completion.