Inline Editing of Item Cost based on discount

Hello,

I am trying to achieve what I think should be a simple thing?  I am new to Netsuite however, so I am unfamiliar with alot of the behind the scenes, and so maybe that is what is throwing me off.

I want to be able to simple – at the line items level, create a new data column in (Transactions line items?) table which is called ‘Multiplier’.  This field is a decimal from 0-1, which then just does what it says – multiplies the item cost by multiplier to get a final customer net price.

So – List price of $1000 with a .8 multiplier = $800.  Should be a simple formula field?  Am i missing something, or is there something working against me that wouldnt allow that to work?

Any advice or guidance here is greatly appreciated.

Thanks!