When I float by myself I will pay for a shuttle. Sometimes I have been known to ask a complete stranger if he would like to float with me so I don't have to pay for the shuttle but use his vehicle to follow me down to the take-out point, then get in his vehicle and go back to where I dropped the boat.
If I float with friends I'm okay with using their vehicles to follow me to the take out if we are just doing a short, say 3-4 mile, float. But if it is a long float, say 10-12 miles, it is a real pain in the butt to have to first drive up to the put in and drop the boat and leave it unattended while you drive the boat and trailer to the take-out. The buddy has to follow you in his vehicle and then you both drive back to the put in.
Then at the end of the day after rowing, and fishing for 10 hours and all you want to do is get to the cabin and relax you know have to trailer the boat and take your buddy all the way back, 10-12 miles, upriver, Then and only then do you get to go home or to the motel and eat dinner and relax.
To my way of thinking that is absolutely no fun at all and if even if it is my best friend and he insists to do it the hard way and not split the cost of the shuttle with me I'd rather float by myself and pay the $30.00.
Another issue I didn't mention is I hate leaving my boat unattended for more than a few minutes. Stuff happens and while we like to think our brethren fly fishers are as honest as a priest I have known people who have had stuff stolen right out of their boats while they are doing the shuttle with a buddy. It only takes a few seconds to steal a pair of $500 composite oars, or an anchor, or whatever else you left in the boat. A couple of times I paid guys who appeared to be honest looking guys who were wade fishing around a ramp $5 to watch the boat for me for 15 minutes while we do the shuttle.
BTW all your friends, and even some you didn't know you had, are going to be wanting to float with you now. Unless you are okay with spending the day rowing them down river I would recommend never to take more than one guy with you on a float. Then you can both fish. Another recommendation I would make would be to tell your float partner the oar lock position is the middle of the boat and if he is sitting in the bow seat then any fish he sees rising in front of the oarlock he can cast to but if it is rising behind the oarlock then those are your fish. Maybe you have really nice friends who would never cast to fish on your side of the boat. My friends on the other hand don't have such manners and will cast to any fish they think they can cover no matter where it is.