Thank you!
I am using Amazon's Product Advertising API to retrieve prices from Amazon. There are a few hoops to jump through in order to get access, but it's the most legitimate means of acquiring their pricing data, so that's why I took that route.
I have not done much keyword research at this time, but I definitely should. I get very little traffic currently -- but I do find the website useful for myself, so that's enough to keep it going!