Don't know what size you need, but would one of these work?
Princess Auto Barrel Dolly. Argh, I can't get a link to work from their search site. Go to
Princess Auto and search 'barrel dolly'. They have 3 available for less than the $50 quoted. What's strange is the larger one is cheaper. I have the 23" one and it works quite well. Just had to lube the wheels a bit.