Each level is basically same, other than the amount of places and Robux players will get, it allows you to create Shirts, Pants, sell them, lets you create groups, advertisements, badges, personal servers, and gives you access to the trade system and mega places.
Builder's Club purchase page on ROBLOX which explains all the benefits and features.
BC FAQs listing many common questions and answers about Builder's Club.
Note: You do not need Builder's Club to develop and create famous games. In fact, a lot of people don't have builders club, and still create amazing games without Builders Club. What Builders club does do, is allow you to advertise your place with more money, giving you a much better chance of getting it to the people who will enjoy and play it. It also allows you to create badges in your game. Creating your game is going to be the same with or without Builders Club, however, if you want to expand your economic avenues though, buying BC is the way to go, allowing for more places, advertising, and other features. Overall, creating your game will be the same. Getting it known well is a whole lot easier with Builders Club.