What other checkbox property can i use to pass a value?

I have this form based entirely of checkboxes, products, these products have a squareSpace value between 1 - 10 because the box where they go ins have a value of 50, so you can only add products until that value is 50 or below.

Everything good so far, each checkbox value give me the squareSpace, but i also need to pass a price value and that is where i'm having problems. Now i can't have both (squareSpace | price) in the value property since i'm adding the squareSpace to determine if the entire order is below 50.

What other property can i use to pass a second value when the form is submitted? i've tried defaultvalue but didn't do it.

Thanks in advance