First, let's calculate how much Alvin will save over the two years.
Alvin saves $250 a month for 24 months (2 years):
\[ 250 \text{ dollars/month} \times 24 \text{ months} = 6000 \text{ dollars} \]
Now, we subtract the amount he will save from the total cost of the training to find out how much his family will need to pay:
\[ 9500 \text{ dollars} - 6000 \text{ dollars} = 3500 \text{ dollars} \]
Therefore, Alvin's family will need to pay $3,500.