These are the price spreads on the goods that I have found so far.
Rice: 27 - 72
Corn: 66 - 144
Bananas: 200 - 300
Ore: 304 - 480
Coffee: 1,280 - 1,920
Rum: 3,725 - 5,016
Silver: 9,600 - 14,400
Gunpowder: 14,755 - 24,000
Buy low, sell high!
If you start off by building a pet store at 5, then building a music player right beneath it, and a bench just to the left of that, you get all of the people to spend all of their money for the first 2 levels. That get's you an extra $1000 each time.
1. Pet store slot 5. 2. Boutique slot 6. 3. News stand far left and bench right after. 4. Upgrade pet store once. 5. Bus stop. 6. Toy store slot 7. 8. Benches and ads - random to slow shoppers. 9. Upgrade toy, boutique and pet to max. 10. Jewelry slot 4. 11. Electric slot 8. 12. Restaraunt slot 1. 13. Furniture slot 3. 14. Supermarket slot 2. 15. Upgrade at leisure. 16. Win all levels. 17.keep it alive