The cost of a commercial kitchen can frighten even a seasoned restaurateur nevermind someone setting up or just expanding from home. Secondhand is the way to go, or was, each time I looked at it (financed 3 kitchens, business share on 2). Buying something for which there is an easy and quick sell on market is where we went each time and then write down the differential immediately to provide a reliable exit cost.
Home based business plans don't work when you add in commercial kitchens as you can rarely ramp up production at sufficient profitability to cover the huge jump in costs.
I did once look at fractional usage but this was in an area where it could have run 24/7/365 without hindrance but in the end we split usage 50/50 on that one.
Without cash and near as damn it proof of ability to sell the increased production, it is unfortunately a money pit.