If you’re looking to do this manually, using a “site:” query on Google is likely your best resource to locate their Amazon seller profile. For example, if I pick a an Amazon seller at random — say “StickARoo”, I’d do this:
Ex Google Search URL: site:amazon.com “stickaroo
I’m able to locate the “At a Glance” seller summary page for StickARoo.
From this, I can derive their seller ID, current active inventory and pricing:
There isn’t a public solution I’m aware of currently to accommodate your request, though I do this type of thing daily for clients.
From an automation perspective, the seller information page could be scraped to harvest the specific ASIN information. Once ASINs were identified, you can use the Amazon API to grab all data (including price) associated with the listings.