Agree with Karina here - If the price/FV of one licence is $100, it'll still be $100 even if the customer buys 100K licences. The total contract value will be different though. If you must: an user event script or a workflow on the sales order to check the quantity then assigns a value (e.g between 1 and 49 = 1) - this custom column can then be mapped under revenue recognition fields to the revenue arrangement and then used as part of your FV formula.