In fact there may be some special roaming offers
from your countries providers or you could use standard data roaming. There is also growing competition in the field of global data SIM cards with package prices.
Both can be interesting alternatives and are also listed (partially sponsored) here, but currently locally bought prepaid data SIM cards still offer the best price-performance ratio.
Still we appreciate if you buy your global SIM cards
via our links to help us cover the cost for this site. :-)