Brad, the condition with lighting you are refering to is called "metamerism". It's where the toners in the paint are seen, sometimes more, sometimes less in the different lights. The two different paints have different toners (even though they may be the "same" color) and in different lights they look different.
Matching a bc/cc color with SS, pretty much impossible. I will tell you right now, that color mixed in a SS isn't top of the line paint and probably a "Value line" and color matches are more often than not, VERY poor. Ok for an overall, but for collision work, forget it.
I am sorry, budget or not, realistically you are going to be blending that color out onto the adjacent panels with BC/CC to correct this. Other than that we are talking about a "butt match", matching and painting the same panels over. This can be done, don't get me wrong but the color matching skill level is going to be pretty high to pull that off. Generally, it isn't even thought of, you prep the adjacent panels for blend and do it, one time, job is done and delivered.
This is the bad part about doing cheap work, you are STILL expected to be better than the cheap price and products should get you.
If you do want to do cheap work, you have to make it REAL clear that it will probably look pretty funky, this is all about communication with the customer more than "body and paint". Every once in a while I have done that cheap work, I make it REAL clear it isn't going to be very good just "better" than the damage they are looking at, but made VERY clear that it won't be "fixed", just "better". The funny thing is when you set it up well like that they are usually thrilled with the outcome, miles from perfect or not.