The first question I have is what do you mean by 1 liter of
nutrient? For each plant like lettuce you will want about 1/2 gallon of nutrient solution per plant. For medium sized plants like basil (depending on how big you want them to get) you will want about 1 gallon minimum of nutrient solution per plant. And for large plants like tomato you will want a minimum of 2.5 gallons of nutrient solution per plant. Personal I would grow each one of those types of plants in their own system. So basically I have no idea how many of each type of plant you are talking about growing, and I have no idea how many gallons of nutrient solution you will need. If you are referring to one liter of nutrient concentrate, all manufactures are different, and I have no way of knowing how many gallons of nutrient solution the 1 liter will make. But I can tell you if your planning to have it shipped to you, you will most likely get more for your money if you get dry
nutrients, rather than a liquid.
Also going back to the system design, I have no idea what type of system/s your planing to use (Drip, NFT, Water Culture,
aeroponic, Flood and drain, wick), or if you plan to combine system types. I don't know if you plan to do regular nutrient changes, or if you are planning to monitor nutrient concentration in order try to stretch out nutrient changes. I also don't know what you plan to do in case of pathogens or a fungus get into your reservoir, or even if your plants get a root disease. Are you going to clean and sanitize the system/s and mix fresh nutrients. Bottom line, there are just too many variables that I don't know to say one liter, or even ten liters will be enough in your situation.
I can tell you that the General Hydroponics Flora series nutrients (gro, micro, and bloom) make about 390 gallons of nutrient solution when you buy it in the 1 gallon concentrates. I also know the verti-gro nutrients (dry mix) makes 5000 gallons of nutrient solution when you buy the 25 lb quantities, and cost about the same as the GH flora series nutrients. With the virti-gro nuts I can have two 50 gallon reservoir, do a full nutrient change on both reservoirs every week, and they (the 25 lb quantities) would last me about a year (50 weeks). Or one 50 gallon reservoir changing every week would last me about 2 years (100 weeks, with the 25 lb quantities of the verti-gro nutrients).