If it's an upgrade, you pay partial value (usually the difference between the two) to attain something of higher value. In this case, if you have $100 donor and want $250 donor, you'd pay $150 extra (the difference) to upgrade to the $250 donor. Since you didn't technically pay an extra $250, you lose your $100 PiP in order to gain your $250 PiP.
If they paid for all three PiP's, good for them. But if not, idt it should be shown. Just too many and looks ugly anyway.