Someone mentioned to me that a bookstore in India called
"Higginbothms" sells video of lectures from Delhi University Maths
department. Is this true? If yes, how can I order them? If no, is
there another way I can buy videos of advanced maths courses (graduate
level)--for less than, say $100 per course? Cheers!

Higginbothams is a large chain of bookstores in India, but I could not
locate any reference to their offering video lectures in advanced
mathematics.

I did find this series:

http://www.videoaidedinstruction.com/advmath.html

Higginbothams is mostly in and around railway stations,  I would not
quite expect them to sell videos of Maths courses though.
there is an Indian satellite which is being dedicated to Educational
Purposes (EDUSAT) and that would have content from various
institutions, but I am not sure if its available commercially to the
rest of the world. afaik its only for Indian unis. details would
probably at the Indian Educational ministry or ISRO sites.

ministry - look in "http://indiaimage.nic.in/" 
ISRO - http://www.isro.org/