If I have 100’s or even 1000’s of products and each product has multiple variations/attributes, how do I do a bulk price update for variations?

For example I might have art prints, in that we have 6 sizes, 4 print options and two ship to locations as attributes/variations. How do I change the price for one size for all those products.

I have my (global) Attributes set up, 3 of them and then several Terms (sub attributes?) for each attribute.

Now when I create a product and add the above attributes and then create the variations, a product may have 25 different variations, each having their own price. For the most part they have the same price for each variation.

But how do I do a global price change for a single (or multiple) variation?