While there are still ways to buy LEGO sets that have long been retired, your best bet is to pick them up while they are still available at major retailers and haven't been marked-up by resellers.

I build the largestest sets Lego has ever released - Diagon Alley, Ninjago City Gardens, the Santiago Bernabéu, the Taj Mahal, Hogwarts Castle, the AT-AT, the Millennium Falcon, the Colosseum ...

This majestic Lego set is a miniature recreation of the famous Taj Mahal built by the Mughal Emperor Shah Jahan. It captures ...