I can bring 30 gallons of tincture to winterzation temps in under a hour using about 30lbs of Co2.
A key is to have steady flow, a diaphragm pump will not preform very well because the flow is pulsing slower as the tincture cools.
Ideally you want to use the gas you create to offset the cost. If you have a Co2 extractor you can purge, fill and run your pumps off of the gas. If you have a grow you can store the gas in tanks like compressed air for Co2 enrichment.
If you can get your Co2 for less than 25¢ a pound then it’s probably cheaper to cool with liquid Co2 vs the electric cost to cool with refrigeration.