Alpha Automotive interview questions

Applied through Zip Recruiter. They contacted me the next day. Went through a brief phone interview where they asked me questions to figure out if I would pass as an individual buying am expensive car for personal use. They had me watch a video about how the process works. Basically, you try to fool the dealers into thinking you are buying a car for yourself. They pay you a commission of $1,000 plus 20% of any discount you get off of the MSRP. The HR person called me back to talk about if I thought this was right for me. I asked the interviewer how they could make money buying cars from a dealership (at retail prices)and paying me a commission and then turning around and selling it to another buyer. It doesn't make sense to me. So they are a profitable auto broker buying their cars at retail prices and paying a commission? Something smells fishy here! I told her a wasn't comfortable. Oh and why are they identifying themselves as Lasalle Auto (not Alpha) on Ziprecruiter?