What card should I use if I were to do a lot of online shopping involving USD?

There is a strategy that I recently wrote about to get cashback on YouTrip; yes, you heard that right! It involves UOB one, Grabpay and YouTrip. You can read my blog to find out more.

To be honest, your spending threshold is quite low. If you can consistently hit $500, try UOB One card (3.33%). I've reviewed it before in my blog; do check it out.

If not, go for the Stanchart Spree (2%) or DBS debit card (3%).

Using a SGD credit card usually incurs around 1% (currency conversion fee) +2% (bank admin fee) = 3%

The forex rate is usually not that favourable, roughly 0.6% additional costs.

So a total of roughly 3.6% additional costs on most credit card (NOTE: this is average, different bank charges different, some charge a bit more... some charge a LOT more)

You can google for most bank charges. For peace of mind, you may just stick to youtrip or its rivals.