Hey y'all. Our Farm is building a new lab. I would like your recommendations on FFUs. Erik recommended the company Clean Rooms Intl) and said they were around $850. We got an email back from Myers Mushrooms and apparently they're selling those units at retail for $1200. Is that the only way to get them? 
We also are considering used ones from a Microprocessor Manufacturer that are selling at similar price. Do you think it would be safe to get a used one if it came from a reliably clean environment? How to know how much life span it has?

Cheaper place to get the American FFU? 
New Chinese FFU?
Or used American?

Any thoughts are much appreciated!

https://www.ebay.com/itm/256195201848