Hi MARS100,
Your score 306 is not so bad and 100% will get ITA within 3 to 6 months.
BUT, If you want improve your score, appear yourself for ielts again and get CLB9.
OR Your husband may appear for IELTS again and try for CLB7.
That depends upon your EE score.
if your EE score is above 320, Then my advice is not spend $500 on ECA done on spouse education just to increase 8-10 points