Need help knowing when to make an offer

[Michelle Terelak]

Hi

I am a newbie.  Brandon Turner suggests analyzing 100 properties to make 10 offers (at the number that makes sense)  to get one deal.  The wall I am running into is when I find my number that works, I don't know how to determine if I should put an offer on the property.  I feel like I can find a number on every property but it is normally much lower than the asking price. I don't want to put a low ball offer in on every house I'm interested in because I'm worried I am wasting the realtors time.  Do you have any recommendations on how I can determine a property to put an offer in on?