Fee to apply for the SBM Smile Card in dollars?

You will pay in Mauritian rupees the amount equivalent to dollars. So you don't need to exchange your money first.

The SBM Smile card is given out within 30 minutes of application, so I suppose they'll try to get as much information as possible from the applicant before issuing one, hence they're asking for mother's maiden name.

If I remember correctly, you get the card in denominations of Rs1000 and they will deduct 8 dollars to activate the card.