Mobal and International Calling Card Combined?

[CCMP]

From some other threads, I see that some folks recommend buying a $49 Mobal phone. However, the cost to call the US from Italy and Great Britain (the two main places we will be going) is $1.50 per minute per the Mobal website. On a prior land trip to Australia, I bought a prepaid international calling card which I used from hotel land lines. I am wondering if it is possible to buy the $49 Mobal phone and then also buy a prepaid international calling card to lower the charge per minute. Is there any way to combine these two options or am I dreaming? Thanks. CCMP