I'm in the process of putting together an equipment list for a culinary incubator. For sauces, condiments and soups I was thinking 20-30 gallon SouthBend direct steam, steam kettle because the building has steam heat. New we're talking like $3700 or $4000. That would put a big dent in the budget. Could one possibly get by with say a few Vollrath 20 qt Double Boilers that run only about $110 each? I was thinking 2 to start. If you use a steam kettle, could you live without it? Would it be essential or merely nice to have? Thanks.