Calculating a "total" when a cost changes between ranges

Major thanks for the quick support, JohnTapley!

This is an excellent link you directed me to that helps explain it. I think I need to let the logic "sink in" a little, but the concept makes perfect sense. I admittedly didn't conceptualize the idea for the negative decimal values starting from 0.065 (-.019 and -.014) and that would have been crucial to making this work. I rarely worked with SUMPRODUCT as well but I believe what I was thinking of would need it in some respect.

One last question:
Since technically the costs are between 0-36000, 36001-64000, and 64001+... would I need to adjust the cost matrix values of L3:L5 to 0, 32001, and 64001? Or am I thinking through this incorrectly?

Thank you again!! I really appreciate your help (especially the link to learn this concept a bit better).