I presently have a 100 amp electrical service in my house I am planning on putting in a hot tub do I need to upgrade to a 200 amp service if so how much would this cost also could I just do a 150 amp service

150A is worthless these days. 200A is nearly the same price so no valid reason to go to only 150A.

Price is impossible to say without knowing where you are and seeing the job conditions.
If it's an easy overhead service expect to pay anywhere from $1400-$3500.