Economy class is definitely not very good value for redemption, not hard to do the math
As to worth it or not, it depends on how you value the miles. For a $2k transaction, you pay $52 and get 2872 miles. That's like $0.018 per mile. Some people on this forum are willing to pay the annual fees of cards for miles at $0.02 per mile.
Not sure what you consider short getaway. So I'm taking SIN - HKG. That's 30k miles for roundtrip economy redemption. That is like $540 based on $0.018 per mile, excluding taxes. If you get promo ticket, currently it states to be "from $258". So you would be better off not using cardup, if you redeem for economy class. At $258 ticket, this works out to $0.0086 per mile.
However, if you redeem for business class, then it is 55k miles for SIN - HKG business class roundtrip or $990 of fees, this would be a better value for money as the fares run up to more than $2k?
Lastly, if you redeem for economy class it is often best not to "pay" for miles, or reduce your cost for miles when you "pay" for them, so the cost has to be below $0.0086 per mile if you are to "pay" for your miles. For example, if I charge $150 to my VI card with the Christmas promo (now fully redeemed), I pay $3.90 in fees, but I get a cashback of at least $2, which reduces the fees by more than half (or even more). This greatly reduces the cost per mile I pay.