Hi @shige3
The page seems to have got removed – the link isn’t working for me either.
It seems that the introduced file upload plugin does not support multiple files
Hope you’ve checked the collections comprising of 12 alternative plugins suggested above.
For pricing you can set up variable products wherein the amount payable will depend on the size chosen. Here’s the guide to creating variable products: https://woocommerce.com/document/variable-product/
Searching around, I was not able to find plugins that convert uploaded images into WooCommerce products. However, you could have some luck searching further in the www.ads-software.com plugins repository, but it is probable that you may have to go for a custom coded solution that meets all the criteria.
You can check for more insights on the WooCommerce Facebook group or the #developers
channel of the WooCommerce Community Slack.
Alternatively, you can consult with a web developer for a custom-coded solution: https://woocommerce.com/customizations/.
I hope you find this information helpful.
* Support for custom coding is beyond the scope of support we are able to provide in this forum. This particular forum is for questions that are related to the WooCommerce core features.