65-70% of ARV

[Ron King]

Hello, 

Why 65% or 70% of ARV?

What is factored in that %, because repairs are factored in after you take 70% from the ARV?

So if i offer a seller 70% of ARV and they ask why 70% what do I tell them? "Because its rule of thumb" I don't think that explanation will go over well.

Thanks for the help on this.