If 4e is any guide, paying permanent costs (wealth is a permanent cost) for a one-time effect is really unpopular.
That is an extremely general statement and, I believe, quite wrong. People happily pay gold in PF and 3E for one-time effects (especially wands of healing).
You're paying a very low price per hit point when you use a wand of healing and in 4e, you wouldn't buy one if such things even existed, since you can patch yourself up between battles with healing surges. Come to think of it, a healing potion in 4e still costs a surge, so there's no benefit to using it out of combat. (In-combat healing is usually as fast and usually heals more.)
A Wand of Cure Light Wounds is incredibly cheap for its benefits, and not being able to top up hit points is so aggravating that PCs will pay any price, including resting after only one encounter, to get that benefit. I don't think that's a fair comparison.