Please try to type in your comments in English because this post is not in the "Filipino Expats Group" forum so other nationalities may be keen on adding their ideas regarding the topic. Their ideas are also valuable to us as regards this topic.
Anyway, adding my two cents worth.....
1. Yes, they are right. Salary grade or level depends on country of origin because it is based on the standard of living in your country of origin. So you will find many Arabs, or even Asians having higher salary than you or even their brothers in race because they have a different nationality now based on their passport. So an Filpino accountant from the Philippines will get a lower salary than an Filipino-Canadian accountant. This is not a racist policy but a policy based on standard of living of country of origin.
2. Calculate your risk. Plan ahead. 700 dollars is not much if you are bringing your family with you. But in the end you may not earn it anyway if you stay in there. Also you don't plan to stay here for a long time. Think maybe 3 to 5 years just to gain experience and then move on or build your own company. But if you become satisfied and it is gainful then maybe you can stay on.
I know its a lot of buts and maybes. I myself spent 6 months before finally deciding to accept the offer and go here. Weigh all your options and most of all pray.
Good luck.