Database prices reflect my efforts researching automobile industry since 2003, compiling quality databases and keeping them up-to-date, plus offering daily customer support.
Databases are targeting commercial use, each year few hundreds companies, programmers and web developers, paying BIG $$ to ensure getting a complete vehicle database, frequently updated and with accurate technical specs. You can also use database for personal use, data analysis, machine learning, academic, etc, but need to purchase at same price like commercial entities.
Stay away from websites offering “complete” databases for FREE download, they are most likely stolen and posted online by other people than original author, or made by careless students who needed only a bunch of data for their studies, such databases are incomplete, contain errors, are outdated, no support or updates are provided. Using databases downloaded freely may destroy your company reputation.