So how much does testing cost per athlete?
With Christian Hesch, he was running races where he was getting $1500 or so by winning secondary races, and ended up making about $40,000 over 2 years while doping.
If a test costs $100 per athlete, it's worth it to test the to 5 men and women, to keep dirty athletes out. If it costs $1500 and you wouldn't be offering any prize money if you tested, I can understand the thinking, but still, what's the point of offering prize money if it's going to go to a doper?
Also, in this case, since the races are associated with a serious professional track meet, that's even more reason to make sure the winners are clean.