Last year I picked up several of these old kits on ebay. I won a Zoltek, the Armored Combat Team, the HUGE Gartan mech, and the equally huge Commando set. At about the same time, I bought several kits from the Dougram series. Interestingly, many of the Robotech kits are Dougram mechs in new packaging.
I haven't been able to bring myself to actually build any of them yet because of their high dollar value, but someday I hope to have a nice little futuristic armored column marching through my home.
By the way, anyone who enjoys the Robotech / Dougram kits may also enjoy kits from the Crusher Joe series and another one called Technopolice. I sure do!