The cheapest stand is a cardboard box with 'V' shaped cutouts in opposite sides. Put some string around this and you can use it as a carrying cradle, with your radio and accessories lying in the bottom or the box.
Of course, cardboard doesn't like getting wet (though a coat of paint can preserve it for a while) – so making the same thing out of wood or plastic sheet makes it more robust.
Some people make pretty stands out of wood to display the boat at home – **LINK**
You can make stands out of PVC piping – **LINK**
It's also a good idea to have some way of protecting your boat in storage and transit. Most people make boxes for this, which can incorporate a stand – **LINK**
Wooden boxes are heavy – here's how I make mine: **LINK**