WNBA rules do not allow players to declare early unless they have already completed 4 years of college or turn 22 before the end of the calendar year in which she was drafted. Only one early entry this year. That was Kelsey Bone, center from TAMU. She was eligible, even tho she had just completed her junior season and still had one year of college eligibility left, becasue she had transferred from South Carolina and had to sit out one year. Thus she had already spent 4 years in college. Griner would have been eligible last year because she would have met the age requirement but she wanted to complete her 4 years of college.
As for salary, the WNBA is not the place to make the big bucks. From the collective bargaining agreement: The maximum salary a player can earn in the WNBA for the 2013 season is $107,500. In order to earn the maximum salary, a player must have six or more years of service in the WNBA. For players with less than six years of service, the most they can be paid in salary for the 2013 season is $105,000. In addition to maximum salary amounts, the CBA also spells out the minimum salaries that WNBA players must be paid in 2013. Players with less than three years of service must be paid at least $37,950. Players with three or more years of service must be paid at least $55,000 for the 2013 season. Average salary is around $72,000.
The players actually can earn more by playing overseas, with some playing both WNBA and overseas. Remember, the WNBA season is the summer and the overseas season is the traditional basketball season of fall thru spring.