The car analogy comes from a calculation for a small single engine airplane or light sport aircraft in the $50,000 range. Using an aircraft loan calculator such as this one from AOPA, we find that you can expect to pay around $400 per month for a 20-year loan with 6.5 percent interest.
Overall, red onions contain a higher amount of antioxidant compounds. They are higher in total flavonoids than white onions and yellow onions are considered to be in the middle. Red onions contain 415 to 1917 mg of flavonols compared to yellow ones, which only contain 270 to 1187 mg.
If you plant onion sets, the sets may be identified only as white, red, or yellow, rather than by variety name. Most growers prefer white sets for green onions. When buying sets, look for 1/2-inch-diameter bulbs, because they're the least likely to bolt.