I'm looking into getting my Authority and plan on using OOIDA.
Like everyone else has told you the first step is getting a insurance quote to make sure it's even feasible for you to get your Authority and move forward.
I was told by Progressive your insurance rate has a lot to do with personal credit score and the state you live in.
With a 2015 T680 and a new dry van I was quoted $10285.00 with 20% down and payments on the remaining balance or $8875.00 one time payment.