Do you actually have all those characters built and ready to use a uniform? If not, just get the most important ones and wait, uniforms don’t last forever. Eventually they’ll get replaced with another new shiny thing that you’ll want to buy instead; then you’ll be kicking yourself over those units you never used. On the converse, certain things have more staying power. P cards affect your entire account and aren’t likely to ever be invalidated, so if you want the black panther p card, that might be a better choice.