Looking for Roof and Chimney Inspector for house I'm buying, pre-contract

Hi all,
We have an accepted offer to buy a house and have done a home inspection. The inspector was not able to do a full roof inspection so he recommended we get a roofer as well as someone to do a Level II chimney inspection. We have called like 15 different roofers and they all say they will not do it until we are in contract. That seems like it defeats the purpose, and the brokers and lawyers are all ok with doing it pre-contract. What is the problem here? Does anyone have any recommendations? This is in the Bronx not Brooklyn…
Thanks!