If your fighting game avatar requires the latest fashions, your best bet is playing Super Street Fighter 4 on the Xbox 360 not the PlayStation 3. DLC clothing purchased for the PlayStation 3 version of the game won't appear to opponents online unless they, too, have purchased the same outfits.
As Capcom explains on its message board:
"The DLC for the newest costumes is additional data that must be put on your machines from the first-party networks (XBL and PSN). When you add new data to an existing product, there are significant costs to do so charged by the first parties. On XBL, those costs were covered by Microsoft. As a result, the data is distributed to everyone, so even if you have not bought the new costumes, you can still see them if you're fighting against someone that has because you still received the new data required to display them. For Sony, those significant costs are not covered. As a result, you only get the new costume data when you actually buy the costumes. Those that don't buy the costumes can't see them, because the new costume data isn't present on your machine."
The company goes on to say:
"The bottom line in this particular case is that Sony would charged Capcom significant fees for distributing the new costume data to users that hadn't actually bought the DLC. Microsoft covered those costs, so the costume data is visible to all there. I wish it were the same all around, but hope this info helps."
Personally, I don't care about costumes for game characters, especially if I have to buy 'em, but I'd think doubly hard if I knew a lot of my opponents would not be intimidated by my sartorial splendor. What about you?