I am just thinking out loud here, but I think the problem lies with Shopify and not with your local browser cache. They will have some upstream cache, probably AWS Cloudfront or similar, that is holding out-of-date versions, I have heard rumours to that effect and other customers have mentioned a similar problem. Some see the latest version, some see a previous version, it appears to depend on the location. Eventually, everyone gets the latest version.
You can test this if you have an interest: open up an incognito, or private browsing, tab. This will open the page with no cached assets, or cookies. If you see the fresh prices then the problem is with Shopify not telling your specific browser to update your local cache. If you still see the old prices then the problem is Shopify not telling their intermediate cache to update.
Regardless, it is a caching problem because the source of truth is the latest Shopify version which does indeed have the latest prices.
It is very frustrating. There is nothing worse than having to ask customers to refresh their cache, its such a customer service cliché.
As for the 10%, its no wonder you saw it as an increase. We will fix this, and thank you for pointing it out. Please contact Kay again and she will give you a 10% discount code so you get the product at the price you first saw.
And finally, thank you for your kind words regarding our pricing. I believe very strongly that our prices should be fair and consistent, and whilst we have updated the majority of our products, we are not finished yet. Next week, Kay and I are conducting a final, grand review of all the products to make sure nothing slips through without being considered. Once that is done, we will be able to move forward from a sound base and reconsider pricing based on customer feedback and competitor analysis.