Sponsor units command a premium because people who might not pass a board can buy them. For example, a sponsor unit would be a good choice for parents who want to buy an apartment for a child who is a student.
http://www.vigrxplus.com/?a=emily83 A sponsor unit may be the best apartment for someone who is not working, or only has a short job history. Basically, if you aren't a candidate for a co-op building and can't quite afford a condo, keep an eye out for a sponsor unit!
http://www.vigrx-plus.org