Quite a few actually.
You won’t be getting implant grade titanium, implant grade steel, solid 14K or 18K gold.
You won’t be getting jewelry with a flawless, mirror finish.
You won’t be getting internally threaded jewelry.
You won’t be getting a lifetime warranty.
You won’t be getting jewelry that is custom fit for your anatomy. T-shirts aren’t one-size-fits-all, why should your jewelry?
But most importantly it won’t look as good as Anatometal, BVLA, or the few other quality companies. And you won’t be supporting a corporate business that doesn’t actually care about you or your safety instead of a small local business such as your local, reputable piercer.