just a single. I make my own using 2 3/8" .190 pipe and a hub setup from a local supplier, it's good for 6,000 lbs.
did you say you were gonna build one for only 300 bucks?? i dont see how this can be done. 3 years ago when i built my 6 x 10 i spent about 900. maybe i didnt understand how you were going about building it.