I have several times had rebuilding teams with very low payrolls where I was able to transfer large amounts to prospect budget to bid for international free agents.
For example, after budgeting for coaches, scouting, medical, training etc. and $20 mil (the max) for prospects I am with $70 mil (by default) in payroll, but my payroll is only $30 mil. I can transfer $40 mil elsewhere but decide to leave $2 mil as a cushion for promotions or unexpected events. So I transfer $38 mil to prospects, reducing payroll from $70 mil to $32 mil and increasing my prospect budget from $20 mil to $39 mil (only a $19 mil increase due to the 50% penalty). It generally takes about $5-6 mil to sign the 25 players drafted in the amateur draft so I am with $33-$34 mil in bonuses to bid for intl. free agents.
Incidentally, I have seen intl. free agents go for as much as $25 mil in bonuses. Since the initial prospect budget is a max of $20 mil, which also has to cover the amateur draft bonuses, that can only happen when owners have had surplus funds (almost always in payroll) to transfer.