What's the difference?

[amade]

I'd appreciate it if someone could shed some light to this. When shopping for stuff in certain shops one can find several weapons or equipments which seem to be very much alike except for certain variations and pricing.

For example, I was looking to restock my arrows and I find:
Pierce Arrow of Steel (common)
Pierce Arrow of Steel (enhanced)

The second is much more expensive than the first but both lists down the same characteristics and damage. What exactly is enhanced?

And sometimes an item may be "...of steel" and another is "...of some other material" but both still have the same characteristics.

Is there any actual difference to them?