I had last tried version 0.2.10, nice progress since!

I installed factorio_alpha_0.4.1-1_all.deb, a few bugs I think:

The internal debian package version number says 0.3.2 even though the game is 0.4.1
The package contains the scenario pack (e.g. /usr/share/factorio/scenario-pack/campaigns ...

OK, that makes sense. I think these intermediate products also explain why sometimes I saw the numbers of possible Science pack 2 above those of the pack 1, while I expected the other way around.

Thanks a lot for your quick answers, keep up the good work!

Well, I would think it should cost 2.5 each time. Given we probably don't want fractional numbers, it could cost alternatingly 2 and 3. Currently it costs alternatingly 1 and 4, which looks like a bug to me, unless I misunderstand something.

In 0.2.9: Science pack 2 is supposed to cost 2.5 iron plates. However when I buy one it costs me only 1 iron plate. When I buy a second one it costs 4 iron plates, then again 1 then 4. So the total is correct, but it's just confusing