While many corkscrews may appear to be the same, not all corkscrews are created equal. Take for example the Chateau Laguiole
waiter's style corkscrews. You can find a number of others that look the same and may even feel the same. However the parts used for the Laguiole are of the highest quality and they are all hand made which leads to much better function and a longer shelf life. The lesser expensive versions of these types of corkscrews are fine and will certainly work. However they may only last a few years and when it comes to those older corks that may crumble upon opening, the Laguiole corkscrews are often the only one that will remove the cork properly.
The same goes for the lever style corkscrews like the rabbit. There are many moving parts in those corkscrews that make them so easy ease to use. The higher end and more expensive models will tend to last a lot longer and not need to have parts replaced as often as their entry level counterparts. So while many of these corkscrews can appear to be identical, once you test out different versions of the same style of corkscrew the difference in cost will become evident.