Why not just buy a 2-month subscription, I bet if you then decide you like that KVS would allow you to apply the price towards a full year..

If you want just flight availability, go for Gold.

If you want award availability, go for Platinum.

If you're a hardcore road warrior who book complex awards and itineraries, or a hardcore mileage runner, then you want the Diammond version for maximum permitted mileage, easy building of itineraries through ITA based on specific fares, routing rules, and round-the-world fares.

If you're looking to save money, most of the information you can get using KVS for a fee you can get online for free. You just need to know where to get it, of course KVS makes it much easier and time-efficient. And you can do simultaneous queries using multiple copies of the tool which is great for efficiently searching awards of flight options during irrops.

Though perhaps if you're seriosu you might reach out to KVS to arrange a free trial of a specific level, though my feedback for you would be not to request 60 days, that seems a bit unreasonable, a week perhaps? Expertflyer offers 5 days..