Fiat Punto vs. Audi A3 !?

Hi, I am about to buy a used car. The money is up to a maximum of 7,000,- €. I looked at two different vehicles. Here are the data and approximate prices: 1.) Fiat Punto 1.2 16V First registration: 2000/2001 Kilometer: approx. 50,000 – 90,000 km kW/hp: 59/80 Gearbox: Automaton Engine displacement: 1242 cm3 Doors: 2/3 Equipment (approx.): ABS, airbag, electric window lifter, radio, air conditioning, fog lights, side airbags, power steering, immobilizer, central locking… Price: 6,200€ – 6,900€ 2.) Audi A3 1.6 First registration 1996/1997 Mileage: approx.100,000 – 130,000km kW/hp: 74/101 Gearbox: Automat Doors: 2/3 Equipment (approx.): ABS, airbag, electric window lifter, radio, air conditioning, fog lights, power steering, seat heating, central locking…Price: 6,400€ – 6,900€ My questions would be: 1.) Which car is more economical? (consumption, tax) 2.) Which car has a longer lifetime? 3.) Why does the Punto cost as about 3 years old car? 4) Is the Fiat Punto so cheap and spartan? 5.) If I drive the car for 3 years, then the A3 would be 10 years old, and the Punto would be about 6 years old. Which would be better on sale? Thanks for your help