Thank you for your comment on this thread. Product prices will always pull from the listed price on Shopify. You mentioned that you have tried changing the product prices directly on Facebook - please make sure to change them on Shopify and allow 24-72 hours for the changes to update.
If this issue persists or if I have misunderstood any part of your message, make sure to grab me a screenshot of what you see and I'd love to continue helping.
Olivia | Social Care @ Shopify - Was my reply helpful? Click Like to let me know! - Was your question answered? Mark it as an Accepted Solution - To learn more visit the Shopify Help Center or the Shopify Blog