I love it when my man buys me pretty panties. So sweet of you to do so for your wife. Plus it totally make you feel like your man wants you bad. Nothing better to get a woman in the mood like making her feel sexy.
I'm very picky about my underwear, in terms of style, fabric, and fit, so I prefer to buy it myself. Sometimes I will get his opinion and intentionally buy things that I know he will like, but I still want to be the one to buy them. I'm the one wearing them, after all. My opinion is the most important. I don't want to be dressed by someone else.