Question

What I need is ‘data-cost’:

<input type="radio" class="selection" data-cost="0" value="One" name="f_1"/>

To increase depending on ‘value’:

<input type="number" name="q_1" id="q_1" min="50" value="50" data-quantity="f_1" />

So for example, if the customer has between 50-100 items, the cost will be 0.53.
So if value="50" I want data-cost="0.53"

and if the customer has between 100-200 items, the cost will be 0.44.
So if value="120" I want data-cost="0.44".

Answer 1

something like this?

$('input[type="number"]').blur(function(){
   if ( $(this).val() >= 50 && $(this).val() <= 100 ) {
     $('.selection').attr('data-cost', '0.53')
   }
})