I do notice a difference, the foreign version does not taste as good.

Just wondering if this is Legal Practice , and do shops really save that much money buying coca cola from Kazakhstan ?

Yeah and it's always flat too.

Some market stalls smaller pound shops often sell foreign versions of soft drinks too.

Never seen it myself. Although my local Off License rather brilliantly sells proper Spanish San Miguel rather than the British brewed version.

Mirinda orange is far nicer than Fanta, if you ever see that.

As long as the ingredients are listed in English there is no reason they can't. I own a chippy and the imported drinks are 30% cheaper in some cases. Most do (Dr pepper always). Some come with little sticky labels you stick on your self. I always stick them on but the local kebab shop does not.

Coke definitely tastes different in different markets. And yes, potentially its much cheaper buying it from eastern Europe or middle east.

Its not illegal but the original distributors are probably breaking T & C. They should however come with English ingredients list.