If the alchemist prepares a large amount, he will always be in a state of fear lest he lose it one way or another. He will have no peace of mind, his spirit will not be tranquil because, on account of his wealth, he fears the king and the people.
Daily Halacha
The poskim stress that it is highly praiseworthy for all members of the household to make every effort to begin Shabbos when the ladies light candles. One reason being there is a Machlokes when Shabbos begins. Some hold an earlier zman than others. Another reason is the danger of "missing the deadline" and inadvertently desecrating the Shabbos. Rav Moshe Feinstein undertook not to ride in a car after candle lighting since it appears to some people as a desecration of Shabbos.