http://singapore.usembassy.gov/add_extr ... pages.html
So the first time I get two page sets for $82, and the second time I can only get one more page-set. But how many pages is a "page set"? Is it what I assume, and just one more page inserted into the binding, so two double sides pages for stamps?The U.S. Embassy may add a maximum of three visa page sets to passports that remain in good condition. If your passport is eligible, we will be happy to add two visa page sets for the price of one (US$82).
I also found it interesting I can get a second concurrent passport. It seems more cost effective than adding pages. I can probably justify it by my business trips to Israel.