From what I understand the easiest way to curb this if you are fixed and low income is not take the insurance, pay the fine which is very low if at all for law incomers, and wait until you get sick and need serious medical attention and then sign up since they cannot refuse pre-existing nor charge extra for it.
You don't understand it. The tax is set at 1% of income for 2014 and then 2.5% of income by 2016. That doesn't sound like much but come April 15th when low income people file their taxes it could be a burden.
Also, you can't simply "sign up for insurance when you get sick". There will be application windows, either every 6 months or every 3 months. And people with pre-existing conditions could be charged higher rates.