What strategies should they use to research and purchase a used car and other high dollar items such as furniture?

The following strategies can be employed to buy high dollar item:
1. Buy during promotional period: during this time, the price will be lower for the same quality. 
2. Buy from a reputable store: in order to ensure that you are buying quality product; reputable stores guards their reputations jealously and so usually offer quality products that reinforce their customers' trust.
3. Priority placement: the type of product one will buy depend on the amount of money that is available. Thus, consideration has to be made in order to choose the type of brand or product that tally with the amount of money one have.
4. One should also have an understanding of the services that one is entitled to after buying the product.