Robotech toys were first brought to the states by Matchbox, who also introduced Voltron. They were later distributed by Harmony Gold. Some of the vehicles were released as part of the Exo Squad series.
@Jay – I grabbed some of the Robotech Revoltech toys when I was in Hong Kong a few years ago for $7 to $10 (US)/each. I even posted a pic of a stack of toys back when I found them: