working example,

last night Spirit of boom $4.60 with a certain mob who were offering the 2nd 3rd deal. BF lay price was $5.90 (at that stage)

So $100 win on SOB
now lay it (what amount?) but if we lay it $100 @$5.90

This is how we stand:

If it wins = lose $490-$360 = $130 loss
If it runs 2nd or 3rd yes we win $100 less commission say $94 Profit
If it loses altogether , we lose $100 but win $94 so $6 loss

So doing it this way you're risking a loss of $130 for a possible gain of $94, which equates to having a $130 bet on a $1.40c favourite.

Having said all that I still feel there is a way to cover all and still make a small profit no matter what , but at a loss as to how to do maths. ?.... anyone?