What you have to do is put in 750k as a "base" amount and for every day you want to leave it put in 75k more. So if you were to collect every 5 days starting with 1.125million would be good. As for the most profit, flax has gone down alot, so herbs are better, and between maples and coal, is up to you, you get more maples, but sell for less profit, the profit margin on coal is about 90-100gp each, and maples is if your lucky 20gp each.