You can hardly see fakes in UK physical stores, but occasionally you can tell from the price and quality that they are fake. You need to be more careful in Indian and Pakistani stores.

Big brand stores will not have fakes. In the UK, the penalties for dishonest sales of fakes are very severe. Selling fakes is definitely not worth the loss. But you must keep your eyes open when buying things on websites such as eBay, even in the UK.