We don't know what the sales of the DLC are, for either gender or any set of costume. Those figures haven't been released. And while I'm absolutely sure the women's outfits sell the most, and I don't think anyone would say otherwise, it's not really a fair comparison because they receive easily three or four times are many outfits as the men do. There's been a grand total of one stand alone, men only set of outfits, while the women have numerous female only packs. Usually what happens now is that the men might get a couple outfits tacked onto a pack primarily featuring the women. (Outside the yearly Halloween set, and the Valentine's Day set that was just released.)
But having said that, Koei Tecmo obviously does see some inherent value in providing the men with fan service outfits. The character of Ein, for example. Almost every single one of his DLC outfits is sexualized in some fashion. And another character, Eliot, actually won one of the costume design contests, and the outfit that resulted from it actually had interchangeable underwear, a feature that previously was only available to female characters. And then you have outfits like Bayman's stripper devil costume, Rig's werewolf outfit that exposes his underwear, Jann Lee's MMA briefs, etc. They do make an effort for the men every so often, they're just not being utilized enough IMO.
But with things like the Valentine's Day pack that just came out, (aka actual swimsuits) their attitudes may be changing in this regard. I mentioned this to Golnei before, you don't accidentally make a speedo. The intent of that content is pretty clear. It may be well into the life cycle of DoA5, and the men might not have the appropriate anatomy to show them off to their full potential, but it is still a step in the right direction. Now I'm hoping that Team NINJA will make a more concerted effort in this regard going forward, and adding some men to DoAX can be part of that effort IMO.
Also, I've seen some people talking about male body physics, or the lack thereof. I posted this in the thread about the DoA5 swimsuits for the guys, but I think it's apt here too...