Redicilous Parts Prices

Me and my partner recently bought a new Ford Fiesta, and all I can comment is - WHAT A JOY! This after we have owned Merc's, VW's, Toyota's etc. Now we are looking for a big car for when our twins are born and after various test drives, the choice is easy - Ford Torneo Connect 7 seater. But there is one problem, we can't afford a new one, and as it is a fairly new model, we are not spoiled for choice when it comes to 2nd hand vehicles. Great was our excitement when we finally stumbled upon a great deal on a Torneo at Human Auto in Bloemfontein, and they also offered me a good trade-in on my 2015 Golf VII. BUT this vehicle only has 5 seats, so I asked them to provide me with a quote to install the 2nd row of seats. The quote: R68600-00!! Ford SA, THIS IS RIDICULOUS!! How is it possible that an optional extra of R1800 can be 38 times more expensive to install afterwards!? No explanation can justify this! You guys are ripping your loyal customers off! I am very disappointed and this makes me extremely nervous about the prices of any Ford parts that my car might need in the future! Please advise, and don't use the weak Rand as an excuse, our currency is not THAT weak!