@runner101 - The good news is probiotics are in the regular cheap yogurt as well as the expensive advertised version of probiotic added yogurt.
The difference is that the companies that make these yogurts have added special probiotics, which they will claim, have added extra benefit.
I do not know if the added benefit is real, is a big change, or a small change. But I have read that people feel that with so many products coming to market that claim to help our health in one way or another it is believed that it would be difficult for the FDA to fully test the accuracy of what each product is claiming.
So I cannot tell you if yogurt that already has natural probiotics in it versus probiotic added to yogurt is better for your digestion, but I have had a doctor tell me to eat yogurt after I was on a course of antibiotics because he said that the medicine will also wipe out my good bacteria which yogurt helps replace.
Plus yogurt is yummy!