Hey thanks for the replies HankoDelicious and JanSteen.
Hanko, your thinking is very much the same as mine. Its great to learn that you however actually are further along the path then me having delt with markets and restaurants. Its basically the same plan I want to follow. I think however I am more like JanSteen, with interest from a bunch of restaurants, and having had a few conversations with organisers of markets in my area.
The price is not given for the linked grow tent, but I agree that it would be marked up quite a bit to be far above what we can do ourselves. It is very big. I spaced it out on my lawn and immediately thought it was too big, especially for what I am wanting to do.
Things I noticed was that the picture looked like it had a concrete base, so throwing this slab down would mean the need for a permanent address and ownership, also, I doubt that this is worked into the cost. Regarding the high volume, I do have access to materials, currently I live in farming country so plenty of straw, cotton husks, wheat stubble, and rice, this will undoubtedly require collection and transport (labour or cost), and also a larger area for processing and prep. I have the ol' 44 gallon drum setup for pasteurisation, but to fill this grow tent would require some serious energy. Also, I asked myself with this tent where the door was to move all this material in without the headache! I once worked for a commercial mushroom farm, their rooms of solid construction had the whole wall as a door, it ran on rollers to open so you could get a forklift in there and other machinery and able to seal tightly once done.
Then, selling all of that regularly, yeah, far too big.
To share with what I have been trying to accomplish, I have been focusing on a much smaller green house approach, but have kept my dimensions within the 3m x 5m range approximately. I intend to take this down the urban agriculture path, so the size is so that it can fit in a garage, but also a shipping container, once I reach that point. The grow tent I designed costs around A$1000 at retail prices. I used a hardware store catalog to estimate prices, and note this is only for the structure (excluded light, air, temp, humidity, (and additional costs like utilities, rent, zoning, and the what not)).
This is where we differ though, and probably to my detriment, is my over complication of ideas, paralysis by analysis. I am fixated on semi automation. And this is where I question whether spending the money or DIY approaches. Things like humidity I have opted for a machine, I can find the model if you want, but it is capable of 30m^3 and has automatic control. Temperature seems to be my main focus now, advice I have received has been go for split air conditioning (as picture in the linked grow tent), although concerns of legal requirements I still need to explore (such as using gas, zoning, insurance), or would I rather try a hot water pipe running through the floor and control it with cold air from outside? It does get pretty hot where I am at, currently, 43C outside.
Now, I am knowledgeable of Arduino electronics, and have managed to build something that turns plug points on off based on readings of temp and humidity sensors, that works already.
As you can probably tell, this is too big already.
Right now, I have a clean room setup like what JanSteen linked, this is where I just run small scale stuff using my current hands on approach, fine tuning those skills, experimenting.
Ill wrap it up there. Pretty long post...