Assuming you're not bad at your job, the biggest thing you have to fear from a temp to perm job is them keeping you temporary forever and never moving you to perm. But this still will be better than the job you are at now.
Now, if you are a slacker (and I am not suggesting you are), it's easier for companies to let go of temps than it is for permanent employees. So just make sure you do your best and you'll be fine. :)
I would risk it and go for the new job. During the probation period do your best and even a little more to impress the company that they made the right decision to hire you. We all have to risk things in our life. Good Luck
If you are a good worker and the company is honest go for it. Probation is to get rid of mistakes, so don't be a mistake. Good Luck!!!
Do you want to be making minimum wage the rest of your life? If you answer no (which I hope you would), it's inevitable you'll have to change jobs at some point. The sooner you do, the sooner you start making more.
You are the only one that can answer this question. How hard will it be to get another job. Most jobs all have a probationary period.