From another thread
This is what my coughpie maths gets me
$105.95 at 5% off is 100.65
You get an extra amex Mr using Plat edge. Costing you 65c per 100 or 0.65% if comparing with explorer
Or s lot more extra points if you can't use amex /PayPal.
So if the place only accepts visa and you get 0.5 to 1 pt per dollar. You get up to 2.5 pls extra for 0.65%
How is my maths
That seems right. One of the few I get stuck with is DEFT for strata fees.
Provided the prepaid visas work ok, it does come out as a slight saving using 10 x $100 cards plus the 3PPD on Platinum Edge