depends on his experience
if he knows what he is talking about im sure its better that he gives them a quick price, that way the customer is more likely to just say yes instead when you call it will be like a sales call and the lead could pop.
the best way infact i think if you can trust your canvasser just make sure he pitches your lead good, and make sure he closes nicely never booking a certain day something within 2 weeks.
find a decent person and do it with him for the first day he will hopefully find out how you like your customers to be!