Zhège duōshǎo qián? means “How much does that cost?” – the most demanding sentence of the training.
You are in a rather untidy shop: there is oil on the floor with an apple in it, and you dance an irritated cha-cha-cha around the puddle. Cha and apple give you zhè, and the irritation gives you the falling tone. You give the woman behind the counter a patronising look, with bits of apple between your teeth: that gives you ge. She invites you to use first names and gives you an apple whose stalk is as straight as the horizon – the German “du” and the apple give you duō, and the horizon marks the level tone. Then she looks at you very softly: shǎo. On the counter lie a packet of tea and a duck leg, which you take up the mountain by cable car: tea and duck leg give you qián, with the cable car marking the rising tone.
Once you have this sentence and the previous one, you can manage in any shop and at any station.