Of course, the high cost of internet access has absolutely nothing to do with people living on dirt floors and not being able to see a dentist (other than the fact that the same common factor (political corruption) has a relationship to both issues.
The problem is, of course, the monopoly system. Lack of competition causes high rates and poor service...and it is also a primary factor in the lack of telecom infrastructure in remote less affluent rural areas.
Monopolies are common in the developing world, Belize is not unique. Actually, in the more populated areas, the Belize telecom infrastructure is pretty good compared to many of its neighbors. The problem is more that the monopoly (or soon to be duopoly) system funnels so much money into pol/crony pockets that there is not enough available to keep the system running as well as it should be.
As you have pointed out, the issue is the huge gap between price and quality of service. If the service is unreliable but the price is low, most people learn to live with it. It's combination of very very high cost and poor service that pisses people off.
We have the same problems with cable in the US. Lack of competition always leads to high prices and bad service.
Internet service quality will go up and rates will go down when the powers that be decide that they will make more money by tolerating competition than by stifling it.