There are various factors to consider when buying a product, but the two main areas must surely be price and quality.

Price is easy - the only three options you have are up, down or same. That's it. Quality is much more involved. Firstly we cannot judge or even quantify the quality of a product if we don't have a yardstick. There are two ways to do this and both have their place. Firstly, find an equivalent product sold by a rival company and compare its attributes with your own product. Better still, obtain all competing products and produce a checklist of each product's attributes, comparing each with the other. Now add your own product to the mix and see where it lands in the quality hierarchy.

A second way of measuring quality is to produce a product specification (the above comparison exercise could feed in to this).