Am I doing Comps Wrong?

[Austin Faux]

So I pull comps in the same neighborhood or within 1 mile of the property.  I make sure they have the same bed and bath, sometimes I'll go down a bath but not up a bath.  I make sure the sq. feet is within 150 of each other, and I make sure the year built is close together.

After that I calculate the average price per sq. ft. of the comps and multiply that by the sq. ft. of the property. I take that number and subtract 20%-30% and subtract estimated repair costs. From that I get my maximum allowable offer, and herein lies my actual question. Why is it that I always end up with a MAO that is bellow what the person initially bought the house at? Is that just the name of the game?

As a side note I do estimate how much they have left on their mortgage and my MAOs are higher then what they still owe a vast majority of the time.

Thanks,

Austin-