How bad is too bad with foundation problems?

[Lisa Gunn]

I have been investing in real estate for 1 year and have purchased three rental houses in the Jackson, Mississippi area. I am interested in purchasing at least 3 more.  There are many properties in the area that have foundation issues due to Yazoo clay. Yazoo clay is a type of soil that moves and fluctuates. It runs in veins throughout an area so one neighborhood can have most of it's houses affected and the next neighborhood would not have it (at least so that it affects the foundations). Some realtors and other investors have tried to scare me away from any property with foundation problems saying that you can pay to fix it but it might come back. I realize that getting a structural engineer or some other professional opinion about the costs involved will be valuable information and obviously, there are different degrees of problem but how do you decide that a foundation is too bad to fix?