I lucked out and found a Husqvarna/Viking rolling tote, unused at a Thrift Shop for $12.00. The only problem I have is that if I load it up with my Janome 11000, it is very heavy. But if I put my smaller classroom machine in it, I can load the rest of the supplies I need around the machine.
So for now, if I am going to a class, workshop or retreat, where my I will want the features of my big machine, I use the tote for supplies and just carry the machine. It is heavy, but weighs less than if I put it in the tote.