An F2 team just runs a car, most of them would be nowhere near being capable of being a Formula One constructor in their current capacity. At most they would be like HAAS where the design and manufacturing of the car has to contracted out (to Ferrari and Dallara in HAAS' case) and then HAAS just assemble the bits and go racing.
IIRC, Jordan Grand Prix was the last team to make the step, which obviously involves getting a factory, buying autoclaves, buying milling machines, hiring skilled fabricators, machinists and composite technicians, hiring design engineers, setting up a wind tunnel (or renting a wind tunnel), etc. It's obviously the step between running a car built by someone else (in the case of F3000/F2, namely Reynard or Dallara etc) and becoming a constructor yourself. Starting a team from scratch v. upgrading a F2 team is obviously not a big difference in either case, as the majority of being a constructor doesn't apply in F2.
Given the value of the existing F1 franchises now, I don't think Andretti, Porsche or Honda would hesistate at paying a one-off $200m dilution fee. It is quite a negligible cost in the grand scheme of setting up one of 13 now-profitable Formula One franchises, (assuming FOM revenue is extended to 13th, unlike the problematic financials of HRT, Manor, Caterham etc of old).
Whether it's $200m FOM fee plus $200m to setup a factory, or $400m to buy an existing franchise like Williams or Sauber, the costs would be quite similar even with the fee.
Certainly true.
Fans can but dream of 26 cars on the grid.
To be fair, Porsche and Honda had the choice to join
and stick around since the 50's, 60's or even 70's when anyone could enter a car and join FOCA (did Ferrari ever join FOCA or was it garagiste only
), yet they foolishly did not do so!
Heck Renault even foolishly closed down their proudly French flagship continental team and bought out and stuck their name on some lowly English garagiste team instead.
[Then they sold it and then they bought it back
again?! The pride of French being carried on a car built by English men and English women -- yikes, same for Mercedes and the pride of Germany... To think of how much the garagistes have achieved in centring the vast majority of the Formula One industry within 100 miles of Silverstone racing circuit -- incredible, absolutely incredible!]