Dynamically updating data-item-price=""

My products have 3 different sizes (large, medium, and small) and these prices are constant across my site $25, $40, and $65. Ideally, if these ever need to update, i’d reaaaaally rather not manually do it across over a thousand instances on my site.

So, does anyone have any thoughts on how I can have the data-item-price="" dynamically update via a predefined number I have someone on my site?

Please elaborate a bit more. Do you have over a thousand products? How do your prices get generated / where do they come from? What sort of webshop is it?