u/Impossible-Canary-54

I purchased a 2024 BMW S1000RR from Facebook marketplace for $18,500 back in March from Indiana. The guy signed off on the title and we filled out a bill of sale. He put the price on both the title and the bill of sale, and when I took it into the DMV to register it yesterday they were trying to charge me $1300 in taxes. I then called the currency exchange today, and they told me it was $850 in taxes. However when I look it up online and on the Illinois department of revenue, apparently there is a flat tax rate of $25 for motorcycles that are purchased private party. Who is in the wrong here? Because Google, the DMV, the currency exchange, and the ILDOR are all telling me different things.