Четко выделил, что труд "сам по себе" не является товаром: К. Маркс Ф. Энгельс Д. Рикардо А. Смит

- Hello! I need a dress for my birthday party. 

- Oh nice! What style would you like? 

-Can you show me something short and tight!

- OK. And what is your size?

- It's 42.

- Here you are. Will be perfect for you.

- Oh no, this color doesn't suit me. Is there a dress of a different color, please.

- Of course, there is. Look! 

- Perfect! May i try it on? Where is the fitting room?

- This way please. 

...

- I love it! And I will take it! How much is it? 

- $113

- Here. Keep the change.

- Thank you! Have a nice day!