One common tactic in the sales process is to emphasis or create a notion of a product or service being a must-have. There are a number of tactics used in sales to create this tension and help prospects over the line. I won't go into these here as it is not very exciting nor interesting.
Often the question is to look at the product or service you offer and justify it's value based on it being a must-have. The reality is that this idea of a product or service being a must-have is old, outdated, and simply wrong. Other than some very basics, and to be clear bottled water is not a must-have, there are limited must have products and services in this society. Plenty of want-to-have but for every product and service there is an equivalent and suitable alternative.
Price is not the purchase driver it used to be. Take a look at Apple products, in many ways inferior and overpriced, yet their sales volumes are ever impressive. Trying to go to market with a new product or service? If you plan to use price as a motivator, unless you are prepared to lose money, there already is or will soon be someone who can provide it for 5 cents cheaper.
Successful sales comes from building a relationship/connection with your clients and prospects. It comes from people understanding why you do what you do and what your vision is. Everything else is secondary. Sell and communicate based on the why and you build a partnership and an alliance. Establish either of these and the end result is a partnership where two parties want to work together. At that point it's simply about aligning of opportunities and timing.
Why do people buy Apple products, because Apple builds cool products and consumers want to be part of the culture. The purchase decision is made based on the 'why' and not the what. Is it a must-have, absolutely not. Are there alternatives - absolutely.