A lot of places have such working databases for finding lowest prices, for example https://geizhals.eu/?cat=mbam4 or http://www.kurpirkt.lv/cena.php?q=rx+470&p1=&p2= . Not sure about the US.
I don't know of a better place than what you said in your OP. Besides selling you something, what would the economic incentive to creating such a database.
A lot of places have such working databases for finding lowest prices, for example https://geizhals.eu/?cat=mbam4 or http://www.kurpirkt.lv/cena.php?q=rx+470&p1=&p2= . Not sure about the US.