I haven't been able to find a plugin that does this or similar to this: product pricing is dynamically fed from an API (for the sake of simplicity, said API supplies a single number: latest_price). Woocommerce retrieves updates from the API every X seconds, and refreshes it on the page until the purchaser commits to buy. When purchaser commits to buy, he will have X minutes to complete checkout.
Is there something similar available? If not, where should I start: modify/extend existing functionality? write a plugin? use something other than woocommerce?