I'm debating between 2 airlines, Singapore and Asiana, to book a round trip SFO-ICN flight.

However, there's a possibility I may need to change my return flight date, so I want to book with the airline with change-flight fees that are minimal to no cost at all.

Singapore says that it's only $20 to rebook + fare differences (but I'm also hearing that there are also hidden costs, such as the extra $50 for talking to a rep on the phone).

I'm also looking at Asiana, and its terms & conditions says that it charges $100 for reissue/revalidation, but it also says "REISSUE FOR DATE CHANGE INCLUDING OAL PORTION WITHOUT CHANGE IN ROUTING/CARRIERS IS PERMITTED FREE OF CHARGE" - so does this actually mean Asiana allows you to change the date for free??

Currently, the fares for Singapore are $930 and $895 for Asiana.