Just make it so value is equal to when it was planted, not when it was sold.
I'll assume you mean when drugs are bought, because it doesn't cost anything to plant. Furdle didn't seem to consider the difficulty in actually going back and forth to sell the drugs when he said this:
Problem is people would mass-store heroin then sell it when people are online..
That only makes sense if someone were to plant a huge farm right beside a drug sell crate (eliminating the risk of going back and forth to sell the drugs), but all the crates I've seen are out in the open so I think there would always be a risk in going to sell.
You could go with one, both, or none of these solutions:
- make playercount directly proportional to the amount you can sell drugs for
- make playercount inversely proportional to the amount you can buy drugs for
If either solutions are used, it would need to be clearly explained in /help when the ideal times to buy and sell are. These solutions would also make the game have a more realistic economy
