A good-better-best approach means offering different levels of product at different price points to cater for different customer budgets and requirements. It is applicable in both consumer and business to business markets.
A good better best range means that customers can choose a product from the 3 core levels (good, better, best) that suits their budget and requirements for features and functionality.
Please note that good-better-best ranging does not mean introducing rubbish product into the range simply to meet a price point or compromising the integrity of the offer or the brand. It is a commercially derived strategy which is about clearly differentiating between the levels of product.
When determining your good better best strategy, remember that you can choose to offer a spectrum of products across a wide or small range of price points. For example a menswear store may stock polo shirts priced at say $19.95, $49.95 and $99.95 to provide for a broader range of customers or across a smaller range such as $79.95, $89.95, $99.95 to provide a choice of premium oriented product.