In many industries, there is a certain hierarchy of events which companies can attend. While there are a lot of really cheap ones, including a number of free ones, there are also a number of really expensive ones with top class speakers, where you may end up needing to spend thousands to attend.
The benefits of attending any event are pretty important. Firstly it allows you to scope out what other businesses are developing, secondly it gives you information on what your competitors are charging for their services, and thirdly you can get a lot of game-changing news about the industry.
What sets the expensive events apart is that, as well as providing all of the previously mentioned information (and information that is often of better quality), the networking opportunities are often significantly better. You can raise raise your own profile amongst some of the biggest groups in the industry, as well as meet a variety of skilled people who may be worth poaching into your business.