There are several providers with cheap call rate in overseas but all of them have call connection fee(flag-fall) 20c-30c for each call you make, which can be avoided using this prepaid sim.
5c/min
Bangladesh, Canada, China, Hong Kong, India, Malaysia, Singapore, South Korea, Thailand, USA (including Hawaii & Alaska), Vietnam
8c/min
Argentina, Austria, Cambodia, Chile, Colombia, France, Hungary, Indonesia, Israel, Japan, Laos, Poland, Puerto Rico, Romania, Russia
10c/min
Belgium, Egypt, Finland, Greece, Ireland, Kenya, Netherlands, New Zealand, Norway, Portugal, Spain, Sweden, Taiwan, Turkey, UK
15c/min
Bolivia, Brazil, Czech Republic, Denmark, Germany, Ghana, Iceland, Italy, Kuwait, Lebanon, Mexico, Nepal, Peru, Philippines, South Africa, Sri Lanka, Sudan, Switzerland, Venezuela
20c/min
United Arab Emirates
It even says you can make video calls (if supported) with the same call rate.
http://www.virginmobile.com.au/mobile-plans-pricing/internat…
28 day expiry, $20 recharge. ==> $20/month minimum spend.
That ends up being pretty expensive. Most of those other resellers have long expiry.