There is a lot more to installing a hot tub outside than the feeder or branch circuit that supplies the piece of equipment.
There is the issue of an insulated equipment grounding conductor, GFCI protection, the raceway in which the conductors are installed, the equipotential bonding grid and the list goes on and on.
It has been my experiences that the installation cost of a hot tub far exceeds the cost of the tub itself. The installation is far more than something that a weekend warrior can attempt.
A tub or pool has treated water and electricity in the same area. To simply install a circuit that makes the water churn about is nothing more than a death trap waiting to be sprung.
Every one asks the question, “can I do this or can I do that” when the question should be, “is this safe or is that safe” but this is not what is on their mind. All they are thinking about is jumping into the water and having fun.
My question is always, “are you willing to place yourself and your family in jeopardy just for the sake of having fun?” If you are then just jump into a pond full of alligators and have all the fun that they will allow you to have.
The bottom line here is simple; if you can’t afford the cost of hiring a professional to make the installation then you can’t afford the tub.