roaming data is a bit like DCC in the aspect that if you're fully aware, and willing to spend a bit of time on the problem then you can probably make savings.

It also penalises impatience - I was chastised by my boss for trying to buy a SIM card from K-Books in ICN...took forever because the sales girl had to link the SIM to the BP I flew in on (must be OZ. They won't sell me the SIM if I present CX boarding pass).

I now more often then not rent a HK$60/day (US$7.7) modem from HK before departure - but that's preparation also.

The only difference is how we perceive the value of the thing we're paying for.
With roaming we see it as a value-added service, for which we either get fleeced by our local phone carrier for roaming or we take the time to make the alternative work.
With DCC, we had a working, relatively low cost solution which is being taken away from us by underhanded means.

http://loyaltylobby.com/2013/08/14/w...ith-sim-cards/