While not a cost estimate, one of the pages linked off of the article ("sample queries") says this: "NOTE that the complete fulltext of all Internet Archive bo

While not a cost estimate, one of the pages linked off of the article ("sample queries") says this: "NOTE that the complete fulltext of all Internet Archive books over these 122 years reaches nearly half a terabyte, so a single query across the entire fulltext collection will use up nearly half your monthly Google BigQuery free quote, so work with the fulltext field SPARINGLY."