And where do the SWAT wannabies fit in between the MilSim'rs and the Skirmishers?
Black BDU are good inside. You can wear it outside if you want or buy a cheap surplus BDU of your choice. Some old OD BDU come around 40$ for a complete kit.
Those things are never waisted. I myself have a couple of BDU, even if I don't play with them often. Im not full of money, but I just buy step by step. When you start playing airsoft and your are not rich, you play with compromises.
When I plan a game, I try to keep in mind that some people don't have all the BDUs, that's why I always do teams that acomodate most of them. Terrorist usually wear mismached BDUs, so it's easyer for those that don't have the complete kit required for the other teams. I think this way of planning is common elswere in canada.