Luck determines the value of dropped items, product chance outside of gear influence, IS partly based on labor points.
I am not sure exactly what you are trying to say here, but to avoid any confusion - value of the dropped items depends on the labor points. More labor points you have when you queue the job, higher the value of the potential dropped item.
Look at the job window like in this screenshot:
It is not luck that determines the value of dropped items, but the labor points determine this value, and this is then reflected as "Luck".
If you are using gear with luck bonus (e.g. Edison horse set +30% Increased Luck) it
doesn't mean that the value of the items you can find is 30% higher. It only means that
the chance to find items (not products!) is higher.
At the same time, more labor points = more products you can find on the job (and more money earned). Product drop depends only on the labor points, and it is only increased by using buffs or gear with product drop bonus. Theoretical example: you don't want to queue a job when wearing gear with product drop bonus which gives you 5 silver pick axes and 50 labor points = 1000% product drop chance (gear bonus already applied), if you can queue it in best gear for the job that gives you 3 golden pick axes, 200 labor points and lower (!!!) 900% product drop chance - because then you can change to gear with product drop bonus that will actually add to that 900% chance that you had when you queued the job. Instead of finding 10 products in 1h, you will find 12 or 13 or 15 (depends what gear you're using). Much better, isn't it?
Use the best gear for the job (most labor points) when you queue the job = highest number of products and highest item value. After you queue the job, switch to gear that gives you a luck bonus or improved product drop chance. this will increase the chance to find items (luck) or increase the number of products you will find on the job.
General rule - queue the job when you're in gear that gives most labor points. When the job ends, you should wear the gear that gives the bonuses (luck, money, product drop, experience...).