Price format for variable products

Hi,
I’m using this plugin for the first time.
For simple products, it works fine, but in case of ‘variable products’ , price is displayed in ‘amount1-amount2’ format. Can it be displayed only in a single amount?
If I don’t add ‘Selling price’ for Role1 & Role2, it shows zero.
And if I add both prices, it shows price in variation ( amount1-amount2)
Is it necessary to add both the prices for both the roles?
I am not exactly clear about the price attributes.

Thanks in advance.