With the average price paid by first-time buyers now more than 150,000, few young people can rely on their salary alone to get a foot on the housing ladder. For most, the only way of squaring the circle is by extracting cash from long-suffering parents or signing up for one of the growing number of shared-ownership schemes.Not Joshua Jackson, 22. He is having an online whip-round instead. The boarding-school-educated graduate of University, London, has set up a website, property.com, on which he is urging people to send him contributions to buy a home