If you're buying a copper watering wand (or making one from copper piping for whatever reason--and I can't see the reason for going to the trouble of doing all that and then scrimping on the head

), they require some care, as do Japanese copper watering cans. Copper is soft. It bends and dents -even the thicker grades. The environment the watering nozzle works in can be hazardous to it's health. You can't throw that stuff around or leave it lying on the ground. Step on a copper wand and it messes things up pretty good, same as the cheap ones.
If you're buying cheap Japanese wands with plastic components (I have gone through a dozen at least), they're inexpensive for a reason--they wear out, or break, if left outside. The plastic head gaskets and shutoff valves can disintegrate in sunlight over a few years, handle them roughly, i.e. l tighten the head to tight , and they can crack. All this is true for western watering wands as well.
FWIW, after spending a lot of $$ on western Dramms,
Haws, etc., over the years, I invested in a
Kaneshin 21" copper wand a couple of years ago. It's been bulletproof, but I'm careful with it. I bring it inside for winter and hang it up above waist level when it's outside and is in use. Comparatively, it outperforms the Drams and Haws I've had. Head has 550 holes, double or triple the number of most western watering wands/watering can roses.