I created a spreadsheet (with functions) that calculates profit while factoring in crop death, transit-load-time, and transit-to-market time for each product. The result is clear. Pineapples. This is partially because you can both harvest and transport Pineapples in a basket. Watermelon and Pumpkins cannot be put in baskets, making them the slowest to profit from.

The table assumes transit-time per crop item to be 5 seconds for all. This is the time to carry the crop to the truck. This could be any number as long as it is the same for each crop.

The major factor is that some crops are basket harvestable and some are not.

Since Grapes and Pineapples are both basket-harvestable, they automatically are competing for the top spot. Pineapples win because you only need to harvest one and the single-item price is higher.

The function for plant-death and crops harvested is basically where there may be some error. I used 20% death rate per "pick". So, each time you pick a crop, you have a 20% chance there will be no re-growth (dead plant). Plus, with each round of picking you do the number is increased as well. My numbers may be off, as it could be 10% or some non-linear value. But keeping them all the same is the real factor. I am open to hear and try your ideas on more complicated functions.

Example: With 10 Pineapple Plants

The function rounds down [Crop Items*(1-(Regrowth Stage*20%)]

First Harvest you get 10 Pineapples.

Function for Second Harvest is
=rounddown(10*(1-(2*0.2)),0) = 6

Function for Third Harvest is
=rounddown(6*(1-(3*0.2)),0) = 2

Etc. down to 1. Then rounding down would get you zero crop.