Men of the UK. If you woke up to a country where about a quarter of men dressed “smart” all the time would you join in? (Details below).

You haven't showed low vs high demand. In this overly simplistic model you have assumed no variable costs. This is a big problem because it effectively means the dry cleaner could supply infinite amounts at every price. Doesn't make sense right. You have showed at the same level of demand the effect of increasing or raising prices. Of course lowering prices means you have more customers. If dry cleaning prices went up to £30 in China people would stop going. At £30 people are still willing to pay for them here. Low demand doens't lead to high prices. High prices leads to low demand. Regardless this is irrelevant to the initial problem. This is a cost issue.