I never had players abusing them, so nothing was disrupted here, but I do find them somewhat dull.
However it's only 1st level wands which can be crafted over and over, 2nd level are already quite pricey in my opinion.
You should consider that by the time these costs become "negligible" to your budget, you might actually be wasting your time casting 1st and 2nd level spells in combat
And thank God there is a level cap for spells which can be put on wands, so there is no chance of finding one in a treasure with too powerful spells on it.
IMXP wands have been used mostly for
(a) offensive/healing spells in combats that last longer than expected, or that weren't expected at all (such as being attacked during sleep)
This is typically only after you've run out of slots. In this case scrolls might work too, but you need them in multiple copies.
(b) tactical spells that don't get used every day but you need to cast on each PC separately, such as Invisibility or Fly.
Again, scrolls could help too but only if you have many copies of the spell. If you use the tactic reasonably often, you probably need those 50 charges and the 50% cost becomes important.