Techno cost ?

[Jefgte]

Reading Logi post about techno, I didnt find the cost of a techno.

http://www.navalism.org/index.php/topic,6440.0.html

Basicaly, a techno cost started in the year is $4 (?)

...Normal research would take 2-3 years to finish...

What does that mean?
Techno cost is $4 or $5 or $6 ?

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With last rules update,
1904 techno cost $4 (?)
1902 techno cost started in 1904 is $4 x 0.9 = $3.6
1900 techno cost started in 1904 is $4 x 0.8 = $3.2

[Walter]

Researching technology has a base cost of $1 per technology per half-year.

... so normally it is $1/HY you spend on a tech. With normally I mean when you start researching a 1904 tech in 1904, a 1908 tech in 1908, etc.
Now it is possible to start researching a tech earlier and of course later as indicated in the table. So if you start researching a 1902 tech in 1904, it will only cost you $0.90/HY while researching a 1906 tech it 1904 will cost you $1.90/HY. A 1914 tech in 1904 will cost you $25.00/HY and an 1894 tech will cost you $05.0 in 1904.

[Darman]

Researching technology has a base cost of $1 per technology per half-year.

... so normally it is $1/HY you spend on a tech. With normally I mean when you start researching a 1904 tech in 1904, a 1908 tech in 1908, etc.
Now it is possible to start researching a tech earlier and of course later as indicated in the table. So if you start researching a 1902 tech in 1904, it will only cost you $0.90/HY while researching a 1906 tech it 1904 will cost you $1.90/HY. A 1914 tech in 1904 will cost you $25.00/HY and an 1894 tech will cost you $05.0 in 1904.

I believe (and please correct me if I'm wrong) that after a certain period of time it is assumed that all countries have gotten a tech (so a tech dated 1900 will be possessed by all nations after 1905, for example). 

[Walter]

Not quite.

Once 15 years has passed since a technology's 'base research-able' date, it is considered to be common knowledge. After that point, it may be researched by any nation as though it were being digested from another nation. Or in other words, $0.25 must be spent on that tech for two half-year turns. Techs that require double the time to research may not be digested in this way, nor can techs be digested this way in secret.