If you look at labels, like I have to for others reasons, you would be shocked to find out how much sugar is added to processed food. Even foods you wouldn't have thought had sugar in do and usually in cheaper brands, eg peanut butter, even chips, crisps. Sugar is often listed under other names, eg dextrose. You often have to pay more for foods without sugar in them.
When I was advised to avoid sugar, one easy quick way was to avoid processed foods. I eat something sugary everyday for a treat now in order not to lose more weight, but I am confident that the rest of my diet (when I'm cooking anyway!) is sugar free.
In the USA it even more difficult to avoid sugar and each time I go there it is reflected in the growing size of the people I meet, who have associated health problems. Eating out is much cheaper there.
Cheap, quick food is full of sugar.
Whatever you think of Jamie Oliver, if he can highlight the dangers of high, hidden consumption, then I'm for it. But I would prefer, sugar free foods could be cheaper than food with sugar in it! Taxing sugar laden food will mean there won't be any cheap food.