Congrats on starting your aviation adventures!
Jeppesen makes several kits for private pilots though most are pretty similar. I'll assume for the moment that you are refering to the Basic/Deluxe 61 kit since you're training at an FBO and not a formal flight school.
The biggest part of the kit is a large textbook that is pretty critical to your flight training. There is plenty of book work involved in learning how to fly. The textbook alone hovers in the $70 to $80 range. Likely included are study guides for the FAA written test, a logbook, a fuel strainer, an E6B, and other items tucked inside a Jeppesen flight bag.
Yes you can earn your license by spending less than the ~$200 they want for the kit. You could also buy all of the included items individually, sans bag, for less than what the kit costs.
But, the FBO might require a kit or at least strongly encourage it so all of its pilots have the same basic tools to learn with. It's hard for instructors to teach if everybody is using different books.