They ran the so-called "boiler room" scam from Majorca to call potential UK investors, City of London Police said.
More than 100 people, many elderly or vulnerable, were conned, with one man handing over £74,000, the force said.
The five men, from Nottingham, were jailed at Southwark Crown Court on Thursday after admitting conspiracy to defraud and money laundering offences.
Det Con Toby Larkin said the jailing of the "callous" gang sends a clear message to like-minded scammers.
People had handed over cash believing they were buying shares in genuine gold mining or pharmaceutical firms - but, both did not exist.
Once their liquid assets were exhausted, some victims were convinced to borrow against their homes, leaving them saddled with debt, police said.
While investors were sent gifts including champagne and chocolates, the gang spent millions on Ferraris, Lamborghinis, a Range Rover, property and trips abroad.
Police started tracking the gang in 2009 as they travelled between the Midlands and Spain, after receiving complaints from concerned investors.
Khan and Wasim Karim were arrested in 2010 as they prepared to take laptops to Palma.
Khan's computer contained victims' account details and records of money transfers. Karim's fingerprints were found on glossy brochures sent out to potential investors.
In July 2011, his brother Rahim was arrested at Gatwick Airport as he returned from Marrakech.
Baugh, who had used false names to set up delivery accounts for VOIP telephones, was arrested in 2011.
Amin, who established a false tenancy for a Nottingham property where brochures were made, was arrested in 2012.
A "callous" gang that made £3m selling shares in fake companies bought luxury cars and holidays, police said.