Lifemiles is currently running a sale where they’re offering 115% and 125% bonuses depending on how much miles you buy (you can top up an additional 10% by joining Inside Flyer for free)
For Cyber Monday, they’re further sweetening the proposition by offering a 140% bonus regardless of how many miles you buy. This makes the cost per mile 1.375 US cents
Again, I wouldn’t recommend you buy Lifemiles speculatively, but this is a great price to buy them if you have a planned redemption in mind.
Remember that Lifemiles purchases count as airline spend for the purposes of bonus mile earnings on the DBS Altitude cards.