Limit 10 per customer in a transaction.
Very useful to buy with your discounted Woolworths eGift cards which you buy at 5% off at various places (apparently only works in some cases - terminals are being upgraded to stop this)
Alternatively buy these with Amex for no cost, get extra rewards points for spending on Amex and then use the prepaid Mastercard at stores where Amex is not available or has a higher surcharge. Note the number of rewards points you get with Amex vs Mastercard will vary depending on the card/s you have.
Yeah depends on airline, dates of travel, 1 way or return, class of travel.
A 1 way from FRA to Sydney is around $10000 on first class, cost me 250k points +$200