No.
Other factors come into play, including product quality, product life, resale or salvage value, aesthetics, safety, need, environmental responsibility, suitability for the need, and more.
A truckload of soap may have the lowest unit price, but it would not be the best buy if you only need one bar. A bicycle may have the lowest unit price, but will not work as a tow vehicle for a 3-ton trailer.
