Visually, one bulb to the next may not look much different at the store, but what’s inside is what really matters. All LEDs have electronic components, this plays a large factor in the price of the bulb, think of this like building a house out of straw vs. building a house out of bricks, you still have a house, but one is made out of better quality construction.
Lifetime of LEDs is also important and this is dependent on the thermal management (ie. heat) of the product. The heat produced by an LED is absorbed into what is call a heat sink, which when effective will lower the operating temperature of the LEDs electronics. If the LEDs electronics operate at too high of a temperate they will degrade quickly and shorten the life of the product.