Quality
Quality, performance and Longevity.
cheap is when something is not expensive. frugal is to be wise and wary of over spending on something.
The cost (obviously) and the material used to make them.
How long it will last and performance.
The different between cheap and expensive spectacles is usually the design of the lens surface. Brand names also play a major role in the price of the spectacles.
the difference between expensive and cheap laptops and notebooks is the quality or quantity of it, usually quality is better because of what it has to offer and usually has warranty on it compared to the cheap laptops usually have more trouble with them
One difference is that one costs more ;-)
The difference between cheaper and more expensive versions of the online game FFXI's currency, gil, is the amount of gil you receive. More expensive versions offer a larger amount of gil.
There is not a significant difference between any type of alcohol.
One major difference would be the price. But with the price often comes better material the expensive biker ring would be made of and better crafting work.
When buying a navigation system, consider looking into reviews and price to determine the best navigation system for your needs. Cheap does not always mean bad quality, and expensive does not always mean good quality.