Hi @nj226406 

s such no such campaign is going on which will give you discounted price on your exam fee .

Only thing I can tell you- if you have participated "Lift Off to Knowledge" and you name get selected in LUCKY DRAW for Phase 3 -> You will get a chance to give a mainline exam free of cost !!

Here is link for "Lift Off to Knowledge" 

https://learning.servicenow.com/lxp/en/general/lift-off-to-knowledge-opt-in?id=learning_course_prev&...

Chance is very very less.. still just FYI.