NT400/hour is very low, even if you are an unexperienced teacher. The only good thing about the job offer from Jordan's is that you are working daytime only - no nights.
As you may have already gleamed - the evenings are the real "prime time" for making teaching money, particularly if you want to teach adults.
The way to really get yourself set up, making a decent amount of money, is to USE whatever school you sign up with - for the visa. Use your free time to take part time work, or private students - which can pay much more than NT400/hour. [I had private compnay classes at night that paid NT1,100 - NT1,350/hour.] If you are motivated, and willing to travel around town, you can set yourself up well. The trick is to get the bare minimum of hours from your visa school, and use your iniative to set up other jobs.
Of course your employer is going to be trying to squeeze the most out of you, so that's why it'e worth choosing carefully, before you commit. You seem to want to be a kids teacher, if that's true, perhaps you might want to look at small kindergartens. They tend to only need you during the day, so your evenings can be free for privates, or a social life.
Kojen is going to be one of the "try to squeeze you" employers. Jordan's is not the best Kiddie program in town. Kojen, Hess are worth trying. Also drop in at Andrew's English School on Hoping East Road, next to Pub 45.