My suggestion here is simple: Interview Buyers.
Interview buyers; find out everything they did and thought about (narrow it down to why you were selected). Either, as a structured and unscripted interview, then aggregate what they tell you. Build personas on those experiences.
1. Take me back to the day when you first decided to solve this problem; what was the trigger to take action?
2. What really changed in you or the organisation?
3. Key is insight into the trigger moment?
4. What did you do first to understand what providers to consider?
5. Content they find useful, words, messages?
6. What did your peers tell you that was helpful to you (what did you learn on the internet or research)?
Our goal is to be useful to the buyer in this process. Look to add value with your insights for them to create a value exchange. Come prepped!