Flat iron experts i have straight fine hair cut in a stacked bob i used a flat iron to get rid of the frizzies?

only, i saw that chi has a volumzing flat iron that will add lift to the roots but i dont want to pay that much... anyone know of one less expensive that will do the same thing? if not volumizing, what about a good one that doesnt damage my hair just to get the frizzies gone? like i said my hair is already really straight so....