As with what Ms. OBrien said, these stores are in it for the money and any employee that values their jobs, especially in clothing stores where commission is involved, would be respectful and helpful no matter who you are buying those clothes for.
It is hard for me to buy female clothing in any store and I've only bought bras and panties, some nail accessories, and waxing stuff. My wife has an issue with me wearing feminine clothing but not so much with underwear, nails or waxing. Of course my situation is a little bit different than most I think(I could be wrong lol). But if I had the freedom to wear whatever I wanted at home and not have to worry about starting a fight or trying to explain it to the kids I would find a few girls that I'm out to, probably my closest sister, and we would go shopping wherever and basically have a make-over day to let out the woman in me that's been hiding for so long. For me, at the moment, there are just to many variables with negative consequences for me personally to go that far with it.
I think that the biggest hurdle to get over is yourself being okay with who you are rather than worrying whether people will accept you or not. Once you get past yourself then you gain the courage to face the world as who you are. I'm still working on getting past the first step as well as others.