You said your own answer in the second part of that thread, for the first part just divide the price by 50 for the savers gives you.

$50/$4.60 = $11
$50/$5.00 = $10



This leaves you $29 to invest on the other 2 chances you could split the money on each or work out percentages but remember there has to be enough left over after your svaers to make a profit from the winners so price could be a factor.