Originally Posted by
redvelvetmartinis
It's still very expensive. I used to this back in the early days as a flying newbie, until I realized 1) it made no sense to pay the full fare and not be able to claim miles for it just cos you upgraded and 2) it didn't cost much more to simply redeem a full ticket on the higher class.
Your 1) is clearly wrong!!! One of the benefits of buying an economy ticket and upgrading using miles is that you also earn miles for your coach ticket (plus the 25% bonus if your are silver or gold). So the net cost of upgrading in number of miles needed is lower than the headline number becasue a) you can get the 15% online discount and b) you will earn 100% or 125% (if you are gold or silver) for the paid economy ticket
Also, note that SQ charges pretty hefty YQ and taxes on award redemptions. When you buy an economy ticket and upgrade, you effectively "save" on those YQ/taxes you would pay on a full redemption.
My advice is to always look at the net cost of the two alternatives - full redemption versus buy economy and upgrade with miles - for your particular itinerary before deciding which one makes sense
For OP, with 1.6 times the miles for 2 award redemptions, buying upgradeable coach and upgrading using miles (with 15% discount) may make that option a viable option.