You may also wish to consider South Africa or New Zealand.
However, the only person who can answer that is you after some research. Depends on the school/operator from whom you hire, how many hours you wish to fly, cost of flights and accommodation etc whilst out there, exchange rate, loss of earnings/leave whilst away, licence validity etc.
But just to help; here are today's interbank exchange rates - and this is one of the major factors in deciding where's "cheap".
USD 1.67923
AUD 1.80574
NZD 2.25191
ZAR 12.5153
Cheers
Whirls