Your first city is a trial, second is practise. The third city is what you really plan. Do not underestimate the power of the market. Sell the items that are laying for no reasons. You can make money as well as clear the stock. Also, keep your sims happy. They will give you more tax than. Listen to their needs. Do not place sewerage plant near residential area, keep Fire station, hospitals, police station intact in the ratio of your population.
All in all, keep your Sims happy at 100%, keep auditing the stock and sell what is of no use. You will make some crazy money.
