Hmm, so even Mobal has cheaper GPRS than GT:
http://www.mobalrental.com/gsm/gprs/?source=0092XXXXN
$19.55/MB is less than ?18 in GT :-P.
(OK, Mobal seems to have 200kB "data debiting" whereas GT 10 KB...)

There's MANY extra roaming supplements. So much for their flat-rates, and plans to reduce the US supplements, they've added lots more instead.

Increasing prices 100% (SMS) or 400%+ (some Caribbean islands) without any notice is going to give some people a shock on their bills (and lose them some customers).