Where to find an API that gives latest pricing of beauty/cosmatics?

I need an API that can gives the latest promotion info of some cosmetic sites, such as https://www.maccosmetics.com/ , https://www.sephora.com/ , https://www.gilt.com/ , https://amazon.com and others. Appreciate your help, guys!

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Yeah sure. I tried to look up the front-end codes of every sites. They are all different. Using this hardcore way of decoding frontpage codes, I barely can't get the latest pricing info of a determained products. Because I don't know when the new product pricing will be updated. Or I can get the pricing by an endless loop program on that determained web page. But some promotions comes with promotion/discount codes. Without a trusty info source, an endless-loop program is useless. That's why I need an API which gives latest pricing info. Maybe someone did it before.