That's the main issue of purchasing products and services for you business, i.e it's almost impossible to gauge the real value of what you are buying until you try it out and can analyze the figures. This is why it's crazy that so many sass providers still require credit cards upfront or have an arbitrary 14 days trial period instead of having a free plan with unlimited trial period. It removes so many obstacles from the founder's decision-making process without costing the provider much money.