Make an offer before analysing?

[Kenny Breeze]

What's up guys, got a question for you. Let's say your a wholesaler and you did a direct mail campaign. You get a call from Jim a distressed owner and you ask questions about the property. Let's say the deal sounds interesting, so my question is should i make an offer on the phone before even estimating anything and send him a contract so you "secure the deal" or should I tell him i'll call you in 3 days after i've analysed the deal fully and then send him a contract when i've run the numbers?