I hear you. On one hand its a shame, on the other, I understand that when the distributors don't want to stock the old and low volume items, the specialty places have picked up that business.
I just got off the phone with the local auto paint supply.
Similar issue with the thinner for the acrylic laquer. I'll have to make some calls - may mail order it. Crazy. But it will be cheaper and probably the same as the original Dupont. Still $50, so not cheap.
Even in the SEM Color Coat, they are somewhat limited. Just not worth it to have a full mixing system. :(