$3.00 
300 pennies
6 half dollars
10 quarters, 5 dimes

$5. 50
10 half dollars,  5 dimes
25 quarters
11 half dollars 
       
$3.75
15 quarters
30 dimes and 3 quarters
6 half dollars and 15 nickles 

 
$6.00
600 pennies
24 quarters
12 half dollars