Is there any easy way to add an attribute to an entire category?

I have a checkbox option:
'Option1' -> {'Value1 (+$2.00)', 'Value2 (+$1.00)'}
and I need every product in category XYZ to have these checkboxes with the given prices. I can add this to each individual product, one at a time, or update the products that already have the attribute, but i don't see how to add the attribute to more than one product at a time.

thanks!
michael