The DC on that second one is way too low. Caster level +5 means the DC for an item made by a level 3 character is 8. To use a wand normally you already need to hit a 20 (see here).

Instead, simply increase the DC by 5. Also, making it useable once per encounter per item makes it incredibly powerful. Basically, you'll never have to buy more than one wand of anything and save a lot of money, especially on healing. That's too much for a mere skill trick. Now, if it were only once, ever, then I could see it.