Newly armed with my new Westpac Altitude Black Amex+Mastercard, a large 100k tax bill coming up, some advice from Cove, and plenty of information from reading all 341 pages of this thread, I'm now ready to start farming points with my good friend, the ATO. Nothing certain in life other than death and taxes, and while I won't be able to avoid death as yet, and I hate paying tax, at least I can try and soften the blow with the taxes
Like others, I too have calculated that with the Altitude Black promo of double points for 3 months, I'll be able to get the return of 0.48c per FF point(transfer to KrisFlyer). This is before any tax deductibility of said credit card surcharge, so in the end, should work out to be just over half that, so somewhere between 0.25c to 0.27c per KF point after taking into account the tax deduction? Awesome value I think. Obviously, if I pay via mastercard, it'll be even cheaper(raw 0.34c per KF, raw meaning before tax deduction), but I'm willing to pay the extra premium to get a ton more points by paying with Amex.
Since I had the spreadsheet going, I decided to see what else was worth putting on the Amex/Mastercard... Going to buy a car, and having already agreed a very good price for the car(already ordered and should be arriving in July) of just over 50k, asked how much to pay via credit card, and was told an extra 2% surcharge. Running this through the spreadsheet gave me a figure of 0.67c per KF if paying via Amex during the double points period, which I think is still pretty good, so going to run that through the Amex as well.
Also, planning to have a wedding overseas soon. Have to pay for that too, Westpac have told me they charge a 3% foreign currency fee for Mastercard and 3.5% foreign currency fee for Amex. This foreign currency fee is effectively the surcharge I'll be paying for the benefit of using the card, and since both Mastercard and Amex earn the same amount of points but Mastercard has a smaller fee, I'll run the numbers through with 3% foreign currency surcharge. During the double points promo, this works out to be 1.0c per KF, which I think would be the limit I'd pay for chasing/farming FF points. If redeeming for J class or First class flights, I think I'd value the points at around 4c per KF, so if I can get them at 1/4 the value, I think that's good value.
After getting the Altitude Black card recently, I also realised that they offered 0% interest on purchase rate for 12 months, which I didn't know before. Free money up till my credit limit for 12 months, what a bargain!
Thanks again to everyone who's contributed to this thread, love your work