When Liberty Media bought F1 early last year, it also bought the rights to junior series F2 and GP3, supposedly the main steps on the ladder to the 'pinnacle of motorsport'.

While GP3 hit the grid in 2010, GP2 first appeared in 2005, replacing F3000. Just two years after its debut, GP2 was bought by F1's then owner CVC.

In 2017, GP2 became F2 - which in fact had been replaced by F3000 in 1985 (still with us?) - however, the move wasn't simply a re-brand, for while Liberty Media had bought the rights to commercialise GP2 it merely had the licence to the F2 rights courtesy of the FIA.

Recently filed accounts reveal that in 2017, F2 made £11.5m ($15.2m) while GP3 made £4.5m ($5.9m).

According to Toto Wolff, a driver seeking to contest a full season of GP3 will need to have around £570k ($750k) with F2 costing around twice that... this compared to the reported £15m ($20m) an F1 team would be looking for.

Then again, F1 teams spend on average £190m ($250m) a year, while F2 teams spend about 2.5% of that and GP3 half as much again.

While F1 teams are obliged to build their own cars, F2 and GP3 are both one-make series, with teams running identical chassis, engines and tyres, thereby heavily reducing spending while at the same time giving a better idea of drivers' ability.

The cars and equipment are bought from Formula Motorsport, a UK-based company ultimately owned by Liberty, while revenue from the series' in terms of sponsors, broadcasters and race hosting, goes to GP2 limited (GP2L) which is based in the British Virgin Islands.

While UK-based Formula Motorsport is obliged to file its accounts for public scrutiny, GP2L, being based in the British Virgin Islands, isn't, which has led to all manner of speculation in terms of how much the two series are bringing in, with one journalist claiming the combined income to be "$300m+" (£227m+).

According to Forbes, the latest financial statement for Formula Motorsport reveals that in 2017, the company "entered into a sale and settlement deed pursuant to which GP2L sold all ownership interests, intellectual property and assets it held, or had developed, in the GP2 and GP3 series to the company for nominal consideration. GP2L also transferred to the company all fees it had received in 2017 in respect of F2 Championship support races, less costs it incurred, in full and final settlement of all amounts owed by GP2L to the company".

The statements make clear that "the principal activities of the company are the organisation and management of the FIA Formula 2 Championship and GP3 Series", and reveal that despite the boost in fees from GP2L, revenue reversed by 27% in 2017 on 2016.

The revenue drop was mainly because the cars used were the same as in 2016 and as a result the teams didn't need to buy new ones, the financial statement confirming that "revenues fell by 27%) in 2017 driven by prior year sales of the new GP3 car and upgrade kits to support the new 2016-2018 cycle".

Sales also fell by 21.8% to £14m ($18.5m), though this doesn't include staff as only three are shown in the financial statements, the remainder employed by FOM.

All in all, Formula Motorsport was left with a gross profit of £1.96m ($2.6m) down from £3.8m ($5.1m) in 2016.

"The directors consider the performance of the company during the year to be both satisfactory and in line with expectations", declare the financial statements.

As we said earlier, with a new F2 chassis scheduled for 2018, meaning that in 2017 teams were using the 'old' GP2 package, and the GP3 package was in only the second year of its cycle, not to mention one less F2 team competing than in 2016, parts and maintenance for both series was lower but "consistent with expectation".

Nonetheless, according to the financial statements: "Lower gross profits of €2.3m (2016 - €4.4m) and gross margins of 12% (2016 - 18%) reflected higher logistics costs and increased FIA fees following the launch of F2... The company has been granted the right to promote and commercially exploit F2 in the period 2017 - 2041."

In other words GP2's rights had no expiry date but two months after buying them Liberty switched them for rights to F2 which will expire in 2041 and at the same time is now paying more to the FIA for those rights than it did for GP2 even though they now have an expiry date and generated no boost in revenue last year.