I'm a real hot chili lover, and yearly grow about 50 plants from about 10 varieties. I'm used to grow 3 plants (of the same variety) in a single 40 liter pot. While I do get good results, I'm still not sure if it's a good idea to put multiple plants in one pot, or just grow one plant per pot.
Let's assume I can only place 10 pots of each 40 liters for space and maintenance reasons. Cost of seeds and germinating them is negliable as 10 seeds cost just max 3 EUR. Cost of potting soil is quite more expensive however, let' say 8 EUR per 40 liter. Would it be a better idea to only put 10 plants in 10 pots, or place 30 plants in 10 pots? Or would another setup be better? What would give the most return to investment, and why?
... EDIT ...
For illustration purposes, these were my plants last year:
21 may 2017: just placed outside (germinated in februari, first grown indoors as we can get frost until may here)
6 july 2017
A single picking of peppers (unfortunately I don't have any later pictures of the plants)
Close up of 2 satan's kiss and a 'peter' pepper.