In B2B, there is more often than not room for negotiation.
In a buying environment where the client explores the market and collects pricelists as a fixed snapshot for shortlisting/decision, it can be challenging to leave the door open for negotiation and being competitive.
As products and price list change often, it is never wrong to say that "we are working on new features and pricing model" and this encourages the prospect to share any missing features or pricing gap with their budget.
I feel this sentence "we are working on new features and pricing model" can be used in all honesty at any given point, and provides either a door to open discussions/negotiations or a FUD element (if potential price increase).