Had a fiend that did this for 5 years. Got into it after he retired for something to do, travel the country, and make a little spending cash. This was back '99-2005, so costs are significantly more than they were then. He had to furnish the truck--1-ton dually. Also had to install the accessories, as in the hitches (fifth wheel, goose neck adapter, and weight distributing for TT), and wiring for 12 volt for trailers with no batteries ( to work the jacks, etc). Also the truck needs commercial plates, and the commercial drivers license. The first couple years he did it alone, stating he really didn't make any money until tax refund time. When his wife retired, they would take a trailer and a motorhome that were both going to roughly the same area. Drop off the MH, then deliver the trailer. Then either dead head back, or since the original plan was to see the country, stay and vacation for awhile and see the sights. After 5+ years health issues forced a change. Plus with over 600k on the truck it would have to be replaced at a substantial cost in order to continue.
I remember him telling me that those that made a living doing this had to treat it as a long haul trucking job. On the road 7-10 weeks at a time, always looking for something to haul back to cut fuel costs. For him it was an excuse to see the country on someone else's dime so to speak. Got to remember they pay "loaded mile" which means paid one way. They have set miles from point a to point b, and in his case I believe he was paid 1/3 up front, and the rest on return. Then the stories about the extreme difficulties dealing with certain dealerships was eye opening at best. Also stories about stopping every so often to pick up trailer parts as they fall off, breaking down on the side of the road, etc.
So yes, talk to some actual drivers, get all the info you can from the company, try to be as informed as you can.