It's becoming rampant, majorly because of trust, they probably got burnt a few times these companies. This is what I suggest
Because of the company size you're targeting, at least you know they have the resources for your service
Offer let's say one month Paid trail. The amount should be really insignificant to them in a way they can risk it and significant to you to cover cost of client acquisition. Achieve some sort of fulfillment in 2weeks, a booked meeting or a prospect inquiry, something reassuring
Option
A complete free Trial ideally 2 weeks that's if you can offer some sort of fulfillment in that time frame, at Most a month.
If you're confident of your service and you have a repeatable framework that gets results you would have to go this route.
Their ask is justifiable, for companies with revenue you mention it's all about building trust and then results. Nothing else really matters if you can show them you can get the results, they would be willing to.