Base Price Rule

Hello

I have got following scenario

Item master has configured with price UoM as  LB,  Base price is set with two valid detail rows for GA  and LB seperately for the same item .  When sales order is entered Price value is pulled by GA and converting into LB instead of pulling LB value from base price set. Say GA base price value is $4.0 , LB value is $ 0.65.  Assume converion 1GA=5 LB,so each LB here pulling as $0.8 instead of $0.65.

So which is right price supposed to be pulled onto sales order ?

Thanks/RAO