The best advice I can give you would be to get to know some of the maintenance and service people at the large grocery chains. You will be amazed at what they end up junking. If you are patient and get to know the right people you will find that a lot of the stuff you need is cumbersome bulky junk to them and they are happy to let you take it off their hands and save them the cost of carrying it to a landfill. Also, some of the better junk/surplus is often sold at grocery auctions. It will pay you to find out who does this and visit a few.
I process deer to fund my charcuterie hobby. I was given about 60 freezer panels and doors if I moved them out of a grocery store within two days. They didn't have to ask me twice and I had them gone in a day. These panels is what I used to construct my curing chamber/cooler/freezer.
I really like how energy efficient these panels are. To cool it I found a junked 2 ton air conditioner unit and married this to a junked 2 fan cooling unit. With this setup I can use it as a freezer or a curing chamber.
Here is how it fit together.
Here is the inside fan unit. This was junked as well but it only needed a few drops of oil on a fan bearing and a little prodding and it worked just fine.
I cool it with a 2 ton Trane air conditioner unit that was also a junker. Needed a new relay which I robbed from another junker. Since these two units aren't exactly meant to work together it took a little modification and experimentation with freon pressures to get it running properly. Also had to add a bypass and another relay to keep the fans from blowing all the time.
This is the finished chamber/cooler/freezer. To control the humidity I use a home humidifier. If I want it really high I just spray the concrete with water first then let the home humidifier maintain this humidity. In all I have about $300 in this unit.
For a fermentation chamber I picked up a bread retarder at a grocery auction for $150.(Stainless steel box on right in picture above) It needed a new plug. I use a small space heater inside hooked to a thermostat and also put a humidifier or spray it down with water and hang wet towels. It also rolling carts which can be rolled into the retarder. Sausages can be hung on smoke sticks on these carts and rolled into the doors of the retarder.(one of the carts can be seen by the door) I think the thermostat cost about $60. So in all I have about $210 in this box and its capable of handling more meat than I can think about fermenting in any two days AND it can also be used to age sides of beef or two whole deer or simply as something to keep the mince chilled in.
I still have a ways to go before I get where I hope to but I assure you I wouldn't be this far if I had not learned that there are very few people out there that really want the type equipment and supplies that you and I would pay dearly for so when we recognize this fact and exercise patience - we don't have to.
I hope this was helpful and good luck.
Patience please, I'm just trying to get on the learning curve.
