how to save P9.00 at nlex

So this is a trick my mom taught me (I actually cannot believe I learned this from her, she's not what I call thrifty)...

Northbound, we pay P42.00 from wherever to Bocaue area, right? And if we are not bound to Bocaue, we naturally go straight to wherever we are heading, isn't it? To save at least P9.00, exit at Bocaue, cross, and enter the Nlex again after getting a new ticket at the toll gate. Viola! I tried it last night, and it was true. Not more than 2minutes was wasted when I did pass by Bocaue tollgate. I paid P27.00 upon reaching Sta. Rita exit instead of the usual P36.00.

I still cannot get the logic, but hey, I saved some hard-earned money! And I shared it here, hehehe...I just hope the exit would not get congested once the other Nlex patrons realize this loophole.