Yes. All cascade is having you do is casting it without paying it's mana cost. Any mandatory additional cost must be paid and any optional cost (ie. kicker) may be paid. If you can't pay the 3, you can't cast it and will have to go to the bottome of your library.
Quote from Magic: the Gathering Comprehensive Rules (01.10.2010) »
702.82a Cascade is a triggered ability that functions only while the spell with cascade is on the stack. “Cascade” means “When you cast this spell, exile cards from the top of your library until you exile a nonland card whose converted mana cost is less than this spell’s converted mana cost. You may cast that card without paying its mana cost. Then put all cards exiled this way that weren’t cast on the bottom of your library in a random order.”
"You may cast that card without paying its mana cost". This is the important part. It does not affect what you do with additional costs at all, only the mana cost itself.
Modern - Green & Taxes:symw::symg:
Standard - Illusions:symu::symb:
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Modern - Green & Taxes:symw::symg:
Standard - Illusions:symu::symb:
"You may cast that card without paying its mana cost". This is the important part. It does not affect what you do with additional costs at all, only the mana cost itself.
Modern - Green & Taxes:symw::symg:
Standard - Illusions:symu::symb: