I know, I know your wondering why in the world would I buy expensive custom Press-On nail sets when I can just go sit in a nail salon for an hour to an hour and a half and get an expensive set that actually lasts a few weeks or more...hopefully. Well here's why. Press-on nails are not only time efficient, (ie. you will spend 15 maybe 20 min or less applying them if you know what you're doing), they are also a heck of a lot easier on your natural nails compared to the expensive acrylic alternatives. If one pops off, you don't have to worry if it takes your actual nail with it...yikes, and although they might not last AS long as professional extensions, they can still last two plus weeks if you take the necessary steps to ensure they are applied right, which will be a blog post of its own. But, rest easy knowing if you do accidentally pop one of those babies off it's nothing a little glue can't fix on the go. You are also able to reuse your press-on sets if you take care of them when removing them. This allows you to stow them away for later use at any given time. You definitely can't do that with professional sets.
Although they are a bit more expensive than manufactured sets, custom sets still give you the uniqueness of a professional product since actual nail artists give life to custom sets. With cheap manufactured sets that are mass produced not only are the art options lacking, you also run the risk of possibly running into someone with the same set...the horror! And since the manufactured sets are cut out of plastic and not made with REAL gel polish or gel products, the are more likely to wear easier and tend to bend and crease with little pressure, good quality customs won't do that. Because they are more fragile, we find that the manufactured sets definitely don't last as long as custom sets that are usually made out of hard gel. They also don't stay on as long either.
With all that being said I think it's safe to say that you definitely get what you pay for after all, but remember when you buy a custom set your supporting a nail artist and a small business which is ALWAYS appreciated.