Strangers not friends arguing for months in small space, no safe.
Friends trained together, all going, safer.
Except that you need the collaborated money between you to actually compensate for training and many other costs,
per person.
Just as well, not all of your friends will actually qualify for space flight.
In fact, very few will be ready from training at any given time to be with you. And some of them might be culled right off the bat in initial exams and such.
Even if all of you make it past all of the training and exams by the time the flight is supposed to happen, which is nigh impossible, there will still be other people who'll qualify better than most of your friends at the time you launch, so you'll still end up on a flight without your friends.
just as well:
Strangers not friends arguing for months in small space, no safe.
Considering the fact that training is specifically ushered in as to rid of most indignant arguing habits, really.
Also, how do you know all of your friends want to go to space?
What if your friends have friends that you don't know that they'll leave behind?
Really, if all your friends go, then you'll be the only ones with all your friends there, because people will have friends that you don't know as well.