The missing piece is whether there is genuine competition. Twelve days is neither proof of a slow listing nor proof that a bidding contest exists. Has the agent said there is another written offer, or only that somebody might waive contingencies?
Also, asking-price comparables are weak...
Also, “works across countries” needs unpacking. Do you need one shared workflow with local variations, or simply access for users in several countries? The first is much harder. I’d ask vendors to demonstrate the same property moving from listing import through assessment and document update...
The most valuable integration is usually the one that writes information back into the existing system, including status, document version and a stable property or case identifier. A rate feed can look impressive while saving little if someone still has to copy the result elsewhere.
How are you...