Same with U.S. residents. But the cost of the visa seems to be different every time I get one. I just budget around $40 - $50 / month for it. You can extend for 16 months I believe, but you can actually extend through Manila for up to 24 months. Again, not totally sure about that as I haven't been here long enough to worry about it (going on my 7th month) but that is what I have been told. Also, things change all the time.