Questions you should think about (assuming you have existing customers)

* Can you run these case-studies past your existing customers' buyers to see what you're missing? Basically why is a use-case, whitepaper not convincing enough?
* Can you get prospects to talk to existing customers or do a walk through of an existing installation? This is very key in high ticket sales, esp where you are making big claims.
* Can you get video testimonials, including walk-throughs of the installs?

On the pricing model for the trial
* How good/measurable is the RoI? If it's very measurable, can you put in a pricing model which goes up if they make/save more money?
* How fast is the RoI? Will they get an indicator in days/months/years? Your strategy will change based on the period
* What is the install cost? To me more than the monthly recurring, the install cost might be a bigger barrier. Can you fold that into the recurring for a few customers?
* Can you offer a 100% refund if unsatisfied after trial?

To me this sounds less like a pricing issue, and much more like a sales/pre-sales issue. I have done technical pre-sales, sales & mktg, and can help with thinking through this problem over a call.