There is currently an opportunity to buy and earn up to 100% extra bonus United Airlines MileagePlus Miles. Before you cringe at the thought of flying on United Airlines, do remember that you are able to redeem them on Star Alliance and other airline partners. All you have to do is to enter your account number and last name to see how much your account was targeted for - the maximum bonus anyone can get at this moment is 100% and this is the best United Airlines has ever offered. Do note that all purchases have to be completed before 12 September 2017 in order to benefit from this bonus.
Each 1,000 block of United Airlines MileagePlus Miles cost USD 30 (SGD 40.90) but there is a Tax Recovery Fee of 7.5% (which you might be familiar with if you bought Mileage Plan Miles from Alaska Airlines a few months ago). The total cost of purchasing 1,000 United Airlines MileagePlus Miles is USD 32.25 (SGD 44) on a regular basis but if your account has been targeted with a 100% bonus, this essentially brings the cost down to just USD 16.13 (SGD 22) when you purchase at least 50,000 miles. Do take note that there is an annual account limit of 150,000 United Airlines MileagePlus Miles so if you wish to take full advantage of this promotion (and assuming you have not purchased any before), you will have to make two 75,000 transactions.
To get a sense of how many miles you actually need for travel, check out United Airlines' spiffy little interactive award chart but if you are departing from Singapore (South Asia), getting to Australia and New Zealand on Business Class can be quite affordable since it only requires 30,000 United Airlines MileagePlus Miles (approx. S$660) one way. If you can find availability, getting there on First Class will only cost you 40,000 United Airlines MileagePlus Miles (approx. S$880) each way.