Sadly the 50A cords are a fortune from dealers. My rig is unique in that its a 50A setup, with no 2nd ac or washer/dryer. Because of that I leave the oem cord in my house. I have a marinco 18" 50a twist lock that adapts to a 15a pigtail on it. Use it plugged in at home and when running the Honda. In Canada that 50A twist lock can be $200-300 so im more comfortable with a $40 adapter and a normal extension cord that runs under my garage door thus cant be stolen. Sad thats the world we live in...they will likely get $20 for the copper.
Daryll