question:  What is the purpose of the example of pianos in Greence?
context: New money: Do local currencies actually work? It might never have occurred to many of us that there are other types of exchange that can stand in for ragged bank notes tucked away in pockets, or other objects that can stand in for those notes. In crisis-hit Greece, where the euro can be hard to come by, businesses and citizens have turned to bartering using a points system where goods like pianos, pot and pans can be exchanged for security services or loaned farming equipment. Timebanks, local exchange trading systems (LETS) and digital inventions like bitcoin can provide alternative ways for people to pay for goods and services when mainstream currencies hit crises. But they will only work if Britons are ready to accept that they have the power to invent their own currency. McCann is a long-time advocate of alternative means of exchange. It's an idea he no longer thinks will work, because the debate, since Brexit, has shifted from the currency issue back to ideas about Scottish independence. She runs the Clacks Youth Timebank, a scheme where 12- to 15-year-olds can earn credit for volunteering. So they printed a currency that would have the same value as the pound, but could only be traded in independent Brixton shops, where the shopkeeper would also have to spend it locally. It can also be used by residents to pay council tax and by employers to pay wages. No two local currencies are exactly the same. The Bank of England does not consider these forms of currency legal tender, but the notes hold value in the same way as a gift-card from a department store, with the same kind of restrictions about where they can be spent. Proponents say complementary currencies boost spending in smaller geographical areas, which can have environmental benefits as businesses cut transport distances to deal with local suppliers. Detractors say they have no real economic impact and work only as a game for the middle classes, who can afford to buy from independent shops rather than chains.
output:  To show how paper currency is not the only way of paying for something
options:  To show that valuable things are appreciated everywhere  To show how paper currency is not the only way of paying for something  To show how much more expensive luxury goods can be  To show a move away from contemporary currency towards a more traditional approach