Patenting is complex and takes time, effort, skill and experience. $99 patents (or even $900 patents) are not worth the paper they are written on. In fact, they probably harm you by giving you a false confidence.
Patents are examined by patent examiners. They reject claims that cannot be justified. A badly drafted initial application will increase the costs of this ‘prosecution’ process dramatically.
To have value, a patent must be enforceable. If you have to sue someone for infringement, it will be worth their while to tear your patent apart and to show that they do not infringe. They might spend hundreds of thousands of $ on this effort, and if they succeed they owe you nothing. In other words, a badly drafted patent is probably worthless.
Many firms quote very low initial costs, but they are not all-inclusive.
Filing a provisional patent is the start of a process. Ultimately, you need to draft and file a non-provisional patent application (which contains “claims”), and then, your application will be examined (scrutinized carefully) by a patent examiner. It is very likely that the examiner will reject some or all of your claims initially. Objections on the basis that your claims are obvious in light of the prior art are extremely common. You must overcome these objections (often by narrowing and re-casting your claims) before any of your claims will be allowed. All of this takes time, effort and skill and costs money.