The 2012 Formula One championship went down in history -- just over 100 days ago -- as one of the most unpredictable and thrilling seasons in the sport's 64-year history.

Sebastian Vettel muscled his Red Bull to the checkered flag to deny Ferrari toreador Fernando Alonso the title at the very last race in Brazil -- by a mere three points -- to become the youngest triple champion.

Can 2013 deliver an even better spectacle? The signs are looking very positive as teams tackle financial reality ahead of major rule changes in 2014, a key driver makes a fresh start, new names line up on the grid and tires once again promise to provide an unpredictable excitement factor.

CNN World Sport takes you through the need-to-know stories before Sunday's season-opener in Australia.

1. Counting the cost

F1 has always been an expensive business but economic downturns across many countries -- including Great Britain where eight teams are based -- have pulled finances sharply into focus in 2013.

Top teams are spending as much as $375 million a year while those at the back of the grid spend around $75 million.

Look at it another way and a team like Marussia can spend $2 million a week compared to an estimated $1 million a day splashed out by the wealthiest teams.

F1 chief Bernie Ecclestone has proposed an annual budget cap of $250 million for 2014 but that won't help the small teams stay in business.

McLaren boss Martin Whitmarsh, who is also chair of the F1 teams' association, has warned that seven marques are already in "survival mode."

There has already been one casualty as Spanish team Hispania dropped out at the end of 2012 because of financial pressures, having not scored a point in three seasons.

2. Pay for a place

The issue of pay-drivers, who bring substantial sponsorship to secure a ride in F1, has also been highlighted in 2013.

Kamui Kobayashi, Timo Glock and Heikki Kovalainen all lost their seats because they didn't bring enough money to the table.

Even worse, Luiz Razia found the cash to take Glock's Marussia berth only to lose it two weeks before the start of the first race when his sponsorship deal hit trouble.

In a further dent to the balance sheets, the entry fee for a place on the F1 grid was increased by governing body the FIA this season. Teams now have to fork out a basic rate of $500,000.

On top of that it costs an extra $5,000 for each point the team won in 2012. Champions Red Bull were charged $6,000 a point, therefore paid at total of $3.3 million just to get on the grid to defend their titles.

3. All eyes on Hamilton

When it comes to the narrative of the season there is one name filling all the pages -- Lewis Hamilton.

A new era dawns for the 28-year-old, who begins his first season without the support of the McLaren team which guided him for the last 15 years.

When Hamilton signed for Mercedes last September it was a huge risk and, even worse, it looked like a huge mistake.

But six months on, it is shaping up to be Hamilton's best move since he passed Timo Glock in Brazil to win the 2008 world title.

The Silver Arrow was the fastest car in testing and got significant mileage on the clock too. If that preseason form translates to the racetrack, Mercedes will be a real contender.

The haunted Hamilton of recent times has gone -- and it's not only because he splashed out on a private jet, new tattoo and dog Roscoe during the break.

In an interview before jetting off for Australia he tellingly said: "It's nice to be somewhere you are really wanted."