Ralph's hairstyle while flying is completely different from the rest of his scenes because the flight sequences were stock footage.
Bill said they found 20 ounces of gold. At $250/ounce, that would be a total of $5000, to be divided by about 10 people, or $500 per person.
It's impractical when out in a desert to remove a bus' engine and have a group of high school students put it back in. It would have been more sensible to take just the battery or distributor.