Check the Added Services on an ISP Offer
As far as connection is concerned, some prices vary due to the service add-ons that most companies offer. Normally these would include free membership to some groups such as online games or discounts at partnered companies. While they may be something tempting, some people are just concerned about getting an Internet connection and nothing else.
So the next time around you find that an ISP is charging so much, read the agreement and package details closely. You may have missed out something on why their package is more expensive than the others. Marketing partnerships are common these days. You may have missed that out.