Is there a cost efficient way to add windows to a brick house?
There are really two options:

Remove the bricks in the area of the new windows and re-set them (after cutting those that need to be cut) back in the right format to give you the needed window opening.
Using a masonry saw (these are easily rentable) cut out a new rough opening for your new windows, set the windows, and then trim around them.

I'd probably do #2 but either will work.